The Volokh Conspiracy
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Yes, Warrants Allow a Search Through the Whole Phone
A comment on a mistaken way to limit computer searches— focusing on People v. Carson from the Michigan Court of Appeals.
As regular readers know, one of the big issues in computer search and seizure law that I often write about is how to limit computer warrant searches. If everything needs to be searched to find the evidence, and information outside the scope of the evidence sought can be used in plain view, doesn't a search of a computer with a warrant result in a general search — the kind that the Fourth Amendment was enacted to prevent. My own answer to this puzzle is that the Fourth Amendment requires use restrictions for digital searches. The whole computer can be searched, but evidence outside the scope of the warrant cannot be used.
In the last year or two, however, a few state courts have tried to limit computer searches through novel interpretations of the particularity requirement. I think this is wrong, and I thought I would explain why.
Consider a recent example from the Michigan Court of Appeals, People v. Carson. In Carson, the government obtained a search warrant to search a cell phone seized incident to arrest as required by Riley v. California. The government had arrested Carson for working with his girlfriend to steal $70,000 in cash from his neighbor's safe. The government then obtained a warrant to search the phone for "records or documents pertaining to the investigation of Larceny in a Building and Safe Breaking." The officers searched the phone and found text messages between Carson and his girlfriend in which they discuss the crime. The text messages were then used at trial to help prove the crime.
The Michigan Court of Appeals ruled in Carson that the warrant had a blatant Fourth Amendment defect—an error so egregious, in fact, that Carson's conviction must be overturned even though his lawyer never even challenged the warrant at trial. According to the court, Carson's conviction must be overturned because his lawyer was ineffective by failing to challenge the warrant, as if the lawyer had made that motion, the warrant would have been deemed unconstitutional and the evidence suppressed as the good faith exception would not apply to such an obvious mistake.
What, then, was the obvious mistake? According to the court, the warrant allowed a search through the entire phone for the evidence sought. This was plainly wrong, the court reasoned, because the warrant should have been limited to the specific apps and file types that the agents had specific reason to believe would have the evidence sought:
[I]t would have been wholly appropriate to issue a warrant authorizing the police to engage in a search of the phone's contents limited in scope to correspondence between these two regarding the crimes; this would include SMS messages, internet-based messaging applications such as Messenger or SnapChat, direct messages sent through social media platforms such as Instagram or Twitter, emails, and other similar applications. The warrant that was actually issued placed no limitations on the scope of the search and authorized the police to search everything, specifically mentioning photographs and videos. Authorization for a search of defendant's photographs and videos, despite there being no evidence suggesting that these files would yield anything relevant, is particularly troubling in light of the tendency of people in our modern world to store compromising photographs and videos of themselves with romantic partners on their mobile devices. Moreover, people usually can directly access file storage systems such as Dropbox and Google Drive directly from their phones, creating a whole new realm of personal information that the police was given free license to peruse. The pandemic also saw the emergence of applications such as "BetterHelp" and "Talkspace" through which people can have text message-based sessions with their psychotherapists, and applications such as "MyChart" allow mobile storage of detailed medical records as well as private conversations between patients and doctors. Simply put, this warrant authorized precisely the form "wide-ranging exploratory searches the framers intended to prohibit." Hughes, 506 Mich at 539 (quotation marks and citation omitted). Indeed, there are likely many people who would view an unfettered search of the contents of their mobile device as more deeply violative of their privacy than the sort of general search of a home that the framers originally intended to avoid.
According to the court, any decent lawyer would haver realized that this was an egregious mistake, so much that the good-faith exception would not apply and the lawyer was ineffective for not litigating the issue.
But the error belongs to the Michigan Court of Appeals, it seems to me, not to the defense counsel. This is the same mistake that the initial Fifth Circuit panel made in United States v. Morton before the en banc court upheld the search under the good faith exception and declined to address the issue on the merits. As I blogged in 2021, in response to Morton,
The place where the phone is located—or maybe the phone itself—is the place to be searched. And you have probable cause to believe the evidence is in the phone. That's all the government needs, I think. It doesn't make sense to limit the government's search within the place to be searched to particular forms of evidence any more than it makes sense to limit the search of tax records in a house to "documents stored on 8.5 X 11 paper" or "items in boxes designed to store records." As the Supreme Court stressed in Ross v. United States, "[w]hen a legitimate search is under way, and when its purpose and its limits have been precisely defined, nice distinctions between closets, drawers, and containers . . . must give way to the interest in the prompt and efficient completion of the task at hand." Everything in the place to be searched can be searched.
I certainly get the Carson court's concern. It's the right concern. It's just the wrong way to address it. The animating idea is to limit what can be seized in plain view by only allowing the government to look in a few particular places in the digital device where evidence is most likely to be stored. If the government is only allowed to search in a few places, the thinking runs, they won't see overly much. And as a result, only so much can come into plain view.
That's why the Carson court is concerned with people having compromising pictures on their phone and apps with communications with therapists. The court is worried about a cost/benefit balance of allowing a search through that stuff: If a search through it is allowed, then the government can use that, disclose it, post it on the Internet, and do lots of other terrible stuff outside the law enforcement mission. That would be bad. And as I have argued before, there's a straightforward answer to that concern: The Fourth Amendment should impose a use restriction on non-responsive data in the digital setting.
But not letting the government look through particular kinds of files makes no sense. You don't know in advance where digital evidence of a crime is going to be. Some apps or file types may be more likely to yield evidence than other apps or file types, but you can't rule them out. Take Carson's concerns with looking through photographs. Based on news stories and cases, it seems to be common for those who steal things to take pictures of what they steal, storing pictures of the loot on their phone. In a case about stolen goods, why should the government be forbidden to search through the photos on a phone to look for that evidence?
It is true, of course, that Riley requires a warrant. But once the government has probable cause and gets a warrant, they should be allowed to search through the entire phone for the evidence based on the warrant just like they can search through an entire house. If the government gets a warrant to search a home for a knife used in a murder, the warrant won't limit the search to the knife drawer in the kitchen just because a judge thinks that this is where knives usually go. The knife might be in the knife drawer, sure. But it could be in a cupboard, or in the bedroom closet, or underneath a floorboard. The warrant should let the government search there, too. The answer is use restrictions, not arbitrary limits on where the government can look.
The Carson court also raises a concern with accessing cloud-stored contents from the phone, but that seems obviously different: A search of the cloud from a phone is a search of the cloud, not a search of the phone. As always, stay tuned.
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But how does that work in the real world? I really need a 256GB iPhone, but I currently have only a 128GB one, so my photos are actually stored in the cloud, not on my phone. But you access them the same way: you go into the Photos app on the phone. Is that a search of the phone or cloud, and how would the searcher even know?
I store nothing on my phone.
But my approach would be not to have my phone access anything on an outside server without my entering a pass-code or bio-print each and every time.
If the police want to search my medical records on MyChart, let them get a warrant to do so.
You can say that is a nuisance for me the user. It is. I also know that my mode of using a cell phone use is not what most people do.
I'm not so sure Don.
It's been 20 years and I went into other things since, but the laws of physics haven't changed. Your smartphone is not really on the internet, it's actually attached to a really long extension cord to a cell phone tower and then you are going through the cell phone company's network before you actually get to the internet per se.
Yes, you have your own IP address, but they own it, they know what it is, and they are keeping track of your usage, for billing purposes, for network diagnostics, and to deal with malefactors. So even if you destroy your cell phone, the Cell Company will have a record that 128.119.8.148 was you (it isn't) and that 128.119.8.148 went to an IP address that comes back to Clouds R Us and then they go to Clouds R Us with a warrant and ask for the files that 128.119.8.148 put there and/or accessed at (specific dates and times).
Ed,
What in the world are you talking about.
What is ON the PHONE is physically there, whether or not the phone has a SIMcard or not. What do you think that the hundreds of GBs are for.
Of course, if I upload data then it is on a server somewhere else.
Can text messages that pass through the provider still be found. Likely yes, so let the police get a warrant for that.
The matter is that stupid criminals leave the evidence in one physical place. On their phone.
"The matter is that stupid criminals leave the evidence in one physical place. On their phone."
To be fair, it can be just as easy (if not easier) for a police agency to get a search warrant for cloud storage for a person. Then the police agency doesn't even need to have physical possession of the phone in order to execute the warrant.
I don't believe that a current generation phone works without a SIM card, although you do have the option of saving stuff on the SD card, which is removable. And FINDING a second micro SD card wouldn't exactly be an easy thing to do, but I digress.
And yes, we'd be in trouble as a society if our criminals weren't so damn stupid. But I'm not so sure the cops are going to need warrants for the stuff that isn't on your phone. Big Tech seems way to willing to help them without one...
The Stored Coommunications Act generally makes it illegal for providers to disclose most content information to law enforcement absent a search warrant.
Phone do work without a simcard. The sim just allows them to access a cellular network and ties it to a phone number, but they can operate on wifi as well where apps like Snapchat or Facebook Messenger will work just fine.
I know that. I have used an old phone in just that way. But one can also turn off the wifi access. Then the question becomes how good is the firewall provided by one's router.
But back to my original comment that is is plain stupid to keep evidence of illegal activity on your cellphone.
"What is ON the PHONE is physically there,"
What's on the Micro SD card isn't anymore once I remove said Micro SD card from said phone.
And I'd like to see the cops find one of those.
Yes, the ATF did solve the 1993 WTC bombing by finding an axle tag on the truck that had carried the bomb, but that is a tag considerably larger that is secured by one of the bolts that hold the differential together, that being a watermelon-sized piece of fairly solid metal.
I'll give them credit for finding it in the rubble, and more for doing the legwork to chase it down, but unless you can get a dog to smell Micro SD cards or find them electronically without either erasing them or outright frying them, I don't know how you would ever find them.
Unless Stupid Joe is still miffed about his godawful stupid Disinformation Governance Board , most providers will offer contracts that get around the IP address and other BIDEN stupidities that have cropped up. Burner phones are used by druggies but that doesn't make all users druggies.
First and foremost, assume that the search is being done by someone competent and not Bubba.
The first thing they are going to do is do the search in a sterile room -- they don't want you to be able to send a signal to scrub the phone so *if* they even turn it on, they are going to do it in what essentially is a Fariday Cage -- a shielded room that will not let electromagnetic radiation in -- or out. Hence the phone can not contact the cloud -- no signal.
Second -- and this is a guess but an educated one based on what they do in searching computers (PCs) -- they are going to mirror the memory. (Think Hunter's laptop -- the FBI has the actual computer what everyone else has is a mirror image of the hard drive.)
And then using the mirror image, you take it apart block by block by block using another machine. (This was 20 years ago, there may be software to do this for you now.)
Third, assuming the searcher(s) have a scintilla of personal integrity, they are going to know where the various files are. The cloud is *not* seamless, it says "go to that server and look for this file there." And if they are honest, they are going to put that -- exactly that -- in the report. And even if they were stupid enough to let your phone get signal (and not from their stingray), they'd know it sent the query to the cloud.
IANAA but I think if they find that you have your graphic kiddie porn of 3 year olds on the cloud (and there are ways to know that), they'd probably get a SECOND warrant and then go get it. But the reference to it would have been on your phone, and you are assuming that you don't have any .temp files stored locally.
The cloud is nothing more than a remote network -- so it's really like back when drives A-E were your local drives and F-Z were network ones, it's very easy to tell where the computer is going to look for something.
A voice mail, an Email, or a message is rarely stored on a phone but is property of the user and is bailment of the associated service provider.
I don't think that prevents them from giving it to the government -- any more than the credit card laws prohibited Bank America from giving the FBI the names of everyone who was in DC on Jan 6th.
See: https://nypost.com/2022/09/14/facebook-spied-on-private-messages-of-americans-who-questioned-2020-election/
Note that we are hearing about this because there are honest FBI agents who are saying "we don't have time for this bullshyte."
Bailment it isn't. If I hide illegal goods in my neigbor's backyard it is irrelevant EXCEPT that the very hiding adds to the criminality.
Why did you put that salacious crap on the cloud? Because you know you are a demonic perv and that is what demonic pervs do.
If I am not mistaken, the FCC and AT&T considered a voice message held in the phone network to be bailment of AT&T before cell phones became common. I believe this legal status made everything simpler from the standpoint of law enforcement.
If a voice message in the phone network is connected to criminal activity, the voice message hardly differs legally from a stolen car that a thief puts in a parking garage.
Yes it does, in three very important regards.
First, even if the thief swapped plates, the cops are looking for stolen cars, including one with this make, model, year, & color. That's enough to run the plate and see what it comes back to.
Second, ever since the 1970s, every car has had a VIN that is visible through the front windshield and you don't need a search warrant (or to even touch the car) to read it or run it.
And third, if it has no plates on it, that's a violation of the rules requiring vehicles in public be registered, and if it still has the hot plates on it, that's a Bingo.
There is no way you can have that level of probable cause relative to a random phone message.
Law enforcement has decades of experience in associating telephone numbers and telegraph users with illegal activities.
See The Suppression of Bookie Gambling by a Denial of Telephone and Telegraph Facilities.
If law enforcement needs access to a voice message that is bailment of AT&T or some other provide, law enforcement knows how to obtain access to this message.
” the voice message hardly differs legally from a stolen car that a thief puts in a parking garage.”
Tell that to the owner of said stolen car…
In fact, if your car is ever stolen, looking for it yourself is not a bad idea.
I was addressing the specific case of a car that is bailment of a parking garage.
It's like Dumb and Dumber, folks.
By consulting your system settings?
"Is that a search of the phone or cloud,"
That's a search of the cloud.
"how would the searcher even know"
Take the phone. Disconnect it from the internet ("airplane mode" or any of several other different methods). Then search it. Your search is now restricted to the phone.
Fun fact...if you get a search warrant for the cloud, you don't need the phone.
"Fun fact…if you get a search warrant for the cloud, you don’t need the phone."
I don't believe there is just one cloud -- and even if you knew which cloud to look in (credit card companies are way too helpful), there's more than just one user. And a LOT of data...
This is so true.
Which is exactly why it is a general warrant and despicable.
The point of the Constitution is to limit government. To say new technology limits government too much, and therefore the limits must be moved, is about as wrong as wrong can be.
I always thought (mistakenly??) that physical searches of, say, a home, WERE still limited. Depending on what is being searched for. So, if you're searching my home for bazookas, then you can look anywhere in the house where a bazooka might be stored. And, if it's a type of weapon that can be reasonably broken into 2 pieces, you can also look anywhere where that smaller piece might be. But I don't think your warrant permits you to search my jar of flour (even though the search there yields a crapload of cocaine). You may not search through a stack of printed material, even though searching there does show counterfeited currency/kiddie porn/bookmaking records/et al. I thought that if you are looking for something specific and physical, your search is limited to areas where that item might be--with the obvious 'in clear sight' exception. So, if you open a closet searching for a bazooka and find kilos of my cocaine, that would be admissible. Or if you find a box labeled "Kiddie Porn" in that same closet, then that would come in. Clear sight, while searching in permitted areas under the specific search warrant.
To find examples of criminal conduct IN ANY FORM strengthens the case against criminal conduct in a specified limited way. Immoral people act immorally and it doesn't exist in a separate container.
Yes, that was my belief as well. A warrant must particularly describe not only "the place to be searched" but also "the persons or things to be seized."
If you are looking for text messages then there's no reason to be going through photos. If you're looking for photos there's no reason to look at the call logs. But if you're just looking for "Any and all records or documents pertaining to the investigation" then you fail the particularity requirements of the Fourth Amendment.
But if you're doing a physical search of a home for say, fentanyl, what areas of the house would realistically be off limits?
The cops realistically would be able to search "everywhere".
If they were hoping to find it, they'd bring in a dog.
And then it would be what the dog found interesting...
Armchair,
Yes. For examples like yours (ie, the items are potentially very very small), then very little should be off-limits in a search. But, off the top of my head; here are some places where your fentanyl search would not be permitted:
1. A stack of paper. You could probably fan them (to ensure that I haven't hidden a few pills in-between the sheets of paper. Or, less likely, that I haven't hollowed-out a cavity, which could hold a bunch of pills. But, you would *not* be permitted to read anything in these papers.
2. My computer and phone. You could physically open up the computer, to check for hidden pills. But you could not power up the computer, nor do any search of my phone.
(I'll note, in response to Davy C; as criminals become more and more technologically-savvy; I expect that it expands the boundaries of a "reasonable" search. It's easy to include text in any digital photo, so I assume that very careful criminals put important text info into photographs. I'm reasonably skilled in Photoshop, and it's easy to put in "invisible" writing onto a photography. You just make the text the exact same color as that part of the image. If you know that I do this, it's easy for you to see the hidden writing. But if you don't know it's there, you can look at all my photos and see absolutely nothing that appears suspicious.) I don't know how to do the opposite--to hide secret photos inside a text document...I'm not sure that subterfuge is even technologically possible, here in 2024.
Criminals are not getting less stupid. Syllogism:
1. Criminals are people.
2. People are not getting less stupid.
3. Therefore, criminals are not getting less stupid.
A bit of a detour but negative syllogisms are logically invalid.
To invalidate this example, it is necessary only to remember that criminals are a subset of people and that less-stupid is an aggregate measure. That makes it quite possible for the subset of people who are criminals to become more stupid while the totality of people remains at the same level of stupidity - it merely requires some subset of non-criminals to become as much less stupid as the criminals are becoming more stupid.
But not letting the government look through particular kinds of files makes no sense.
It made good sense during the Stamp Act crisis. One of the objections was that too much personal stuff had to be presented for stamp tax review. No 4A then, of course. Maybe that experience had something to do with later.
I think that's addressed by "describing . . . the persons or things to be seized" rather than "describing the place to be searched".
This seems [ I'm being nice and Dale Carnegie-ish ] seems to call into question the whole business about state laws regulating social media platforms. If you can do what you want with phones , where is the difference with social media in general ?
I have heard that police who want to search everything in a house, not evidence of a specific crime, will add something small to the list of items to be searched for. If the search warrant says "rifle" police can't open a pill bottle. If the search warrant says "rifle, ammunition, bullets, and spent ammunition" they can. (This example is made up.)
If the warrant for a phone says "child sex abuse material, specifically an MP4 video of size 13964021 bytes depicting ...." then a computer can find it without finding anything else. No need for humans to look anywhere except in a file of exactly that size. If the warrant says "records or documents pertaining to the investigation of Larceny in a Building and Safe Breaking" then human investigators can and must open figurative pill bottles looking for it.
So I was looking through the decision, and I was wondering about the following testimony:
The witness was reading from a text message, but this was oral testimony. How did he pronounce that, exactly?
1943 was WWII and they needed the copper for the war, so they made 1943 pennies out of steel. But they had some copper blanks left over from 1942, so they used them and then went to steel. Those are rare and quite valuable.
The 1943 steel pennies largely disappeared because people confused them with dimes, back when 9 cents was real money.
I think the Carson court is right and you're wrong, Professor. Your "use" limitation is barely a protection. It allows the government to rummage around inside a phone (and any cloud accounts the phone connects with) and argue "plain view" or get another warrant based on what they'd seen.
Warrants should be particular. If the government believes the evidence is text messages, the warrant should limit their search to files and apps which are used for text messaging. I wouldn't go so far as to say the government should be required to specifically name which apps, but the particular purpose of the search and the kind of evidence they expect to find should be clearly stated in the warrant.
I agree. The "use" limitation has already proven ineffective in the foreign surveillance context. Why would anyone expect it to be more effective here?
Never been a fan of particularized search warrants. If the suspect is engaged in crime all his various storage places over which he has dominion should be fair game
Kinda putting the cart before the horse there!
“specific apps and file types that the agents had specific reason to believe would have the evidence sought” is *not* the same as “only allowing the government to look in a few particular places in the digital device where evidence is most likely to be stored. ”
File types (like images and videos) can be anywhere on the phone, while a “place” on the phone corresponds to a subdirectory, or cloud storage. In other words: if the warrant allows images, the police can search anywhere, but if the warrant does not allow images, files of type .jpg cant be opened, wherever they are on the phone.
I read this post and think Kerr is very confused how technology works. The MI Court got this right, even if we don’t like the remedy.
“You don’t know in advance where digital evidence of a crime is going to be. Some apps or file types may be more likely to yield evidence than other apps or file types, but you can’t rule them out. ”
Ummm. no… This is an argument to throw out the whole idea that search warrants should be “particularized” and allow law enforcement to rummage through the whole house, the garage, the car, and dig up dirt, because you never know where evidence of a crime is going to be!
For that matter, lets let the FBI rummage through and seize 700 safe deposit boxes during an “inventory”: https://cdn.ca9.uscourts.gov/datastore/opinions/2024/01/23/22-56050.pdf
Hell to the no.
Search warrants have to be “particularized” whether law enforcement likes it or not. If they don’t have a reason to search through “images” they don’t get to look at nudes of my wife. Nor do they get to open files to BetterHelp, or texts to my attorney.
Granted… If they do have a warrant for “images” those files could be anywhere on the phone, but they are designated with a file type that tells some other app how to decode them.
"but if the warrant does not allow images, files of type .jpg cant be opened, wherever they are on the phone."
So renaming x.doc to x.jpg means it is protected from a search?
Would the search be limited by an include list ('you can only look at .jpg or .png') or an exclude list ('you can look at everything but .doc')?
If I write an online confessional app for Catholics that writes a .confession file type, and those are off limits, why wouldn't enterprising crooks just routinely rename things to that?
I'm not really a fan of the police getting full access to all the data on a phone, but limiting it seems technically pretty hard.
You point out that the warrant would not refer to file extension but to type, i.e, image text. It can simply say all data files. Meaning that the police cannot try to run executables.
I'm not sure I see the same distinction. Consider the executable compiled from this code:
int main() { printf("Fred's body is buried under my shed"); return 0; }
The police don't need to run it to see the incriminating information.
I'm not sure I understand the objection even if they do run it. For example, you can defeat trivial analysis of strings in the code by, say, combining two bit patterns at runtime to generate the string. I remember extracting a fellow's password who tried to do that once by simply setting a debugger breakpoint :-). If the warrant lets the police look for all the records of my drug dealing, ISTM they should be able to look at all the bits that might have that info, whether encrypted, hidden in code execution, hidden in images using steganography, concealed by spreadsheet macros, hidden in microdots or whatever.
it makes the file unreadable (try it). Also, hard to impossible to do on android or IPhone without special software. You would have to change the file back to the correct extension before you opened it to read it and then change it to the unreadable format when you closed it. I dont even think this is possible on iOS.
"it makes the file unreadable (try it)."
???
We may be looking at this differently. I'm a programmer, and being able to read the bits has nothing to do with the filename. I've never played with iOS, but I've never met an OS that won't let you do an open() and read() (or whatever the OS names those functions) for arbitrary filenames.
I think you are looking at this as an end user, not a programmer.
Yes, this is in fact the rule for premises searches.
United States v. Ross 456 U.S. 798, 820-821 (1982).
No the warrant has to specify what you're looking for, if you're looking for an airplane you can't look in a closet. The FBI got smacked down by for doing something similar (opening boxes they werent supposed to open), we'll see if the Supreme Court takes it up. Don't hold your breath.
But here we’re looking at a phone, and what a phone has is bits. And bits are pretty small ????
Yes, if you’re searching for an airplane you can search any where on the premises that could contain an airplane. If (as is more likely) you’re searching for evidence of drug dealing or murder or fraud or a burglary, you can search anywhere that could contain that evidence. Why would or should there be a different rule for electronic devices than for physical premises?
"The whole computer can be searched, but evidence outside the scope of the warrant cannot be used."
At a fundamental level, this raises the "dead little girl" problem, and the judiciary strives to avoid it. The practice of the courts 'suppressing' evidence at all is still very debated amongst judges, and is a relatively modern innovation (that some say should be reversed).
The 'dead little girl" problem is when an illegal search turns up evidence of a crime (often unrelated to the one under investigation). If a search of a car trunk, for example, is unconstitutional, then its 'fruits' must be suppressed. But what if the police find a dead little girl in the trunk? It is black letter law that the results of an illegal search cannot be used to justify the search. But is a judge *really* going to find a search that turned up a dead little girl "unconstitutional" and suppress the evidence? Or is s/he going to legally approve of the search -- law be damned.
For example, what if the cell phone search in this case had revealed child porn? It is easy to say "well, that can't be used as evidence," it is much harder to actually do that. There will be a firestorm of criticism for the judge and the 'law' (reducing the 'legitimacy' of both). So judges bend the law in favor of admission of evidence, and thus law enforcement is encouraged to even further press the limits, and so on ad infinitum. And this does not even touch issues around derivative use of illegally gathered evidence.
Summarily, the idea of allowing the search and excluding unrelated evidence sounds appealing. But in practice, it is often problematic (to say the least). Far better to prevent a search than to try to remedy its over-expansiveness (ounce of prevention, pound of cure) --- thus an argument that the scope of the search should be limited at the outset, as opposed to permitting a wide search and trying to limit its effects. Of course, precisely how to limit scope presents its own problems.