To Spy on a Cheating Spouse

Use software, not gadgets.


This article is part of Reason's special Burn After Reading issue, where we offer how-tos, personal stories, and guides for all kinds of activities that can and do happen at the borders of legally permissible behavior. Subscribe Now to get future issues of Reason magazine delivered to your mailbox!

In the unfortunate event that your marriage does not last, it may at least end amicably. Or it may not, in which case its final days might need to be accompanied by the kind of aggressive electronic surveillance that once was used only by three-letter federal agencies.

But be warned if you're thinking about snooping on your spouse: A little-known section of federal law enacted in 1968, 18 USC 2512, makes it a crime to manufacture, assemble, or even possess any "device" that is "primarily useful for the purpose of the surreptitious interception of wire, oral, or electronic communications."

Section 2512 goes beyond merely regulating whether any such device is used for good or ill. Instead, it's a far-ranging prohibition on everything, up to and including advertising, an eavesdropping device, based on the premise that unlawful wiretapping will be less prevalent if the tools are less available. Service providers like AT&T and Comcast are exempt. So, of course, are police, other government agencies, and their contractors.

The legislative history from the 1960s reveals that Congress wanted to ban products such as microphones disguised as wristwatches, as well as so-called infinity transmitters that send audio from a room over a phone line, giving the snooper an effectively infinite listening range. The danger of a "martini olive transmitter" was also cited, perhaps by legislative staffers who took the early James Bond movies a little too seriously. In the 1990s, federal prosecutors successfully invoked this law against The Spy Factory, which operated 16 retail stores that sold bugging and wiretapping equipment to the general public.

But thanks to Section 2512's practically antediluvian origins dating to the era of mainframes and punched cards, a loophole has been growing wider every year. That's because the pre-ARPANET statute only bans eavesdropping hardware. Congress revisited the law in 1986 as part of the Electronic Communications Privacy Act but ended up leaving Section 2512 intact.

If someone sells a laptop, phone, or home assistant with preinstalled software that spies on the user without his or her knowledge, that likely violates Section 2512 since those are surely all "devices." Computer code is more slippery. One federal district court in Ohio concluded in 2008 that "software alone…does not fit into this definition."

Martini olive transmitters may be illegal (and imaginary), but Find My iPhone isn't.

In our increasingly networked world, this oversight offers a remarkable escape clause—and a useful reminder of the unreliability of politicians' predictions of the future. Today, any electronic device with a microphone or camera that's connected to a network can, with the right programs installed, become a bug far more potent than the infinity transmitter of the '60s. Yet restricting the use of computer programs raises First Amendment concerns: What about open-source projects? Could the state ban a book containing a printout of source code? (Undaunted, the U.S. Department of Justice invoked Section 2512 last year in its indictment of a researcher accused of creating and distributing the malware known as the Kronos banking Trojan. The case is ongoing.)

The upshot for those who suspect something is amiss in their relationships: If you're going to spy, do it via software.

Important and annoying lawyerly reminder: Installing snooping software may violate laws other than Section 2512, the relevant laws may change by the time you read this, and your local prosecutor may be


good friends with your spouse, if not already sleeping with him or her. The bullet points below are guidelines, but you should proceed with care.

Recording conversations: Be selective about where you live. Some states, including California and Florida, require everyone in the conversation to consent. The rest allow surreptitious recording if one person consents, and fortunately, that one person can be you. Some apps, like Automatic Call Recorder for Android, can be configured to preserve every phone call you make and receive.

Tracking vehicles: GPS trackers are tiny magnetic transmitters, typically battery powered,


that you can buy for as little as $30 plus a monthly fee. From an app or web browser, the user then monitors the vehicle's movements. To optimize for legality, be the sole owner of the target vehicle. Joint ownership is second best. If the only name on the title is your spouse's, don't say we didn't warn you.

Bugging backpacks: This little-known technicality lets you place a bug in your child's backpack to eavesdrop on nearby conversations. It can be legal, as long as you're in a state with one-party consent. The loophole exists because you, a parent, have the authority to grant consent on your minor


child's behalf. New York's highest court ruled in 2016 that if a parent has "a good faith, objectively reasonable basis to believe that it is necessary," he or she may create a secret "audio or video recording of a conversation to which the child is a party."

Tracking phones: Surreptitious installation of spyware that tracks the whereabouts of your spouse's mobile device may not be prohibited by Section 2512, but it can violate other laws.


Consent vitiates this problem, so create an account, with your spouse's knowledge, for the whole family to use—an iCloud account on iOS devices or a Google account on Android. For Apple products, make the iCloud-linked account the primary account, which allows you to use the "Find My iPhone" feature. On Android, go to "Accounts" under "Settings" and add the family account. At that point, as long as you're logged into the family account, you can type "find my phone" into Google and get a location fix. (Remember to turn on Location History, too.)

Watching online: Wiretap laws generally shield information while it's being transmitted.


You're not the FBI, so don't engage in illegal wiretapping. But reviewing files stored on a shared computer used by both spouses isn't wiretapping. Nor would it be wiretapping if you happened to boost the size of the browser's cache, or made sure the browser history was automatically backed up on a regular basis.

Recording video: A surprisingly large number of spouses respond to suspicions that their partner is cheating by aiming a hidden camera at the marital bed. Proving adultery in the form of a H.264/MPEG-4 movie is not a good idea, however. If discovered, the best outcome is a sizable payment disgorged to the spouse recorded in the act during civil litigation; criminal prosecutions are also likely. (One


exception is Mississippi, where an ex-husband learned of his ex-wife's torrid lesbian affair with her new roommate. In an attempt to win sole custody of their minor daughter, he snuck up to the women's cabin and snapped photos through the window of an intimate moment. Although the man was promptly sued for invasion of privacy, the Mississippi Supreme Court ruled in 1999 that "reasonable people would feel [the ex-husband's] actions were justified in order to protect the welfare of his minor child.") Non-Mississippians might try the Reconyx MS7 camera instead. It's camo-painted, battery-powered, WiFi-enabled, and has the resolution and shutter speed to capture license plates. Stick it in a tree and aim it at your driveway, not your bedroom.

Protecting yourself: Do the opposite of the advice above. Your car's title should be in your name. Wipe your cellphone. Avoid shared computers. Use a Chromebook and turn on two-factor authentication. Consider additional security measures as they become available.

Perhaps the best advice is to think twice before going down this path at all. To the extent it lets you avoid the legal gray areas surrounding electronic surveillance, staying together can mean staying out of jail.

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