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Volokh Conspiracy

The Fourth Amendment and querying the 702 database for evidence of crimes


(Michael Williamson/The Washington Post)

An interesting Fourth Amendment issue has come up in debates over the reauthorization of Section 702 of the Foreign Intelligence Surveillance Act. This is the authority, some will recall, that allows the government to collect from inside the United States the contents of communications of foreigners reasonably believed to be outside the United States without obtaining a warrant. Here's the question, as I understand it: If a foreigner (a non-United-States person, in the statute) is communicating with a U.S. citizen inside the United States, and the government has collected the communications between them under Section 702 by targeting the foreigner, what are the Fourth Amendment limits on querying the database to find evidence of criminal activity committed implicating the United States person? In other words, after the government has collected the contents under the national security authorities based on the non-U.S. person, what are the limits on switching over to a criminal query that targets the U.S. person?

As I understand the intelligence community's position, it takes the view that querying the database is always okay because it's not an additional Fourth Amendment search. The Fourth Amendment governs collection of the contents of the communications, but not the separate query. From Q&A posted earlier this year:

Querying databases containing Section 702 information does not result in any new acquisition of data; it is instead only an examination or re-examination of previously acquired information. Therefore, those queries are not separate "searches" for Fourth Amendment purposes. The IC queries its databases to more quickly and efficiently sort and identify communications already lawfully collected, such as information potentially related to a terrorist plot against the United States, without having to sift through each individual communication that has been collected.

I don't find this persuasive. As I understand this, Section 702 raw data has been collected but not yet observed. In Fourth Amendment law, it has been "seized" but not "searched." See Soldal v. Cook County (1992). As a result, the data maintains the Fourth Amendment protection it had before it was copied.

It's true that, after data has been exposed to human observation, it has been searched and Fourth Amendment search rights expire. Once that exposure has happened, the data can be used and reanalyzed in any way the government wants without it being another search. See Illinois v. Andreas (1983). But the mere copying of data without human observation is a seizure but not a search, I think. That's why courts scrutinize how the government searches images of seized hard drives or the copies of email accounts obtained from service providers. If the data has been copied but not searched, querying it is a search. Or so it seems to me.

Granted, there is a circuit split right now on the private-search reconstruction doctrine that might be relevant. The split concerns how much is "searched" when a private party sees a file on the hard drive: Is just the exposed data searched, or the file, or even the entire physical storage device? It's fair to assume, although not entirely obvious, that the answer to that also sheds light on what is searched in the government context. But even so, it seems hard to believe that a court would say that observing some files in a massive government database of unsearched contents extinguishes all Fourth Amendment rights in that data.

If I'm right about that, then the query through the raw 702 database requires its own Fourth Amendment justification. I'm not sure what warrant exception could apply, though. It's a query for criminal investigative purposes, as I understand the hypo, so no national security reasonableness exception could apply. It's targeting the U.S. person's communications, so presumably it's outside the reasonableness framework unpersuasively invented by the Ninth Circuit in the Mohamud case. Maybe there's some other way to get around a Fourth Amendment warrant requirement here, but it's not clear to me what it is.

I'm not saying I have the answers to this question. And maybe I am misunderstanding the question itself. But based on the public discussions I have seen about what is happening, I worry that there is a lot more of Fourth Amendment concern here than the government is acknowledging.