Hyper-Vigilance: When It Is Worth It and How to Do It Right

The top two rungs of the ladder cost real money, time and friendships. They are worth it when someone specific is trying to find you. They are theater when the threat is a mood. A Faraday bag in the glove box does nothing if the phone that rode in your pocket all day kept a location history in your account. A burner phone does nothing if you text your mom from it.

The threat: who is actually after people, and how

Threat modeling when the risk is real

Start with Threat Modeling or EFF's Your Security Plan if you have not, and come back with a name or a group written down. Then answer two more questions about that name. What can they already reach? And what happens if they find you?

The numbers say the likeliest answer is someone you know. The Bureau of Justice Statistics estimates 3.4 million people age 16 or older were stalked in 2019. Two in three victims, 67 percent, knew the stalker, and about a quarter were stalked by a current or former intimate partner. Women were stalked at more than twice the rate of men. And 80.1 percent of victims were stalked with technology: unwanted calls and texts most often, and about 14 percent tracked with an electronic device or app.

That changes what a threat model looks like. A data broker knows your address. An ex knows your passcode, your mother's maiden name, which coffee shop you like, and whether the car's app is still on their phone. Someone who once had your phone in their hands, or shares a family plan, a cloud account or a car account with you, starts far ahead of any stranger. Make a list of every account and device that person has ever touched. That list is your real attack surface.

Good reasons to climb: a stalker, an abusive partner or ex, credible threats after something you published, an activist role that has drawn organized attention, or a family member in public office who is receiving threats. Weak reasons: general dread, a podcast, or wanting to feel prepared. Weak reasons get Levels 1 to 3, which stop most of what actually happens to people.

Stalkerware and the shared account

Stalkerware is an app hidden on a phone that reports to someone else. The FTC says it can track location, record calls through the microphone, read texts and email, see photos and watch browsing, and that these apps hide behind bland names like "System Service." In 2021 the FTC banned SpyFone and its CEO from the surveillance business, saying its apps let buyers secretly see a phone's photos, texts, web history and location. NNEDV's Safety Net project adds screenshots, camera activation and call forwarding. Safety Net also says almost all phone stalkerware needs physical access to install, so the question is who has held your phone, open, for a few minutes.

Often there is no app at all. Safety Net warns that someone with access to your cloud account may not need stalkerware to watch you. A shared Apple or Google account, a synced photo library, a family location-sharing group or a car account (see Vehicles, Travel and Trackers) can report just as much. The FTC lists warning signs: fast battery drain, unexpected data use, a phone that runs hot or restarts. The strongest sign is behavior. The other person knows where you went or what you said without being told.

Here is the trap. Removing stalkerware or changing a shared password tells the watcher you found out. Safety Net warns that "some people may escalate their abusive behavior" when stalkerware is removed, and the FTC gives the same warning. The tech fix comes second. The safety plan comes first.

How separate identities get linked back

A compartment is a second identity kept apart from your real one. It fails when any single detail connects the two, and the research on re-identification shows how little that takes. In 2000, Latanya Sweeney at Carnegie Mellon found that about 87 percent of Americans, using 1990 Census data, could likely be singled out by just ZIP code, gender and date of birth. In a 2006 paper, Arvind Narayanan and Vitaly Shmatikov showed that someone knowing only a little about a Netflix subscriber could find that person's record in the "anonymized" Netflix Prize dataset of about 500,000 subscribers, and by matching against public IMDb ratings they re-identified users and exposed details as sensitive as apparent political leanings.

Neither study needed a hacker. Each joined two ordinary data sets on a few overlapping facts. Your second identity faces the same math. The usual joins: logging in to both identities from the same browser, a shared recovery phone or email, a reused username or profile photo, posting from both at home on the same Wi-Fi in the same minute, a writing habit only you have, and a friend who tags the private account from their real one. One login links everything, and a link made once cannot be unmade.

Being followed in person

Physical surveillance by a determined person looks ordinary up close. The same vehicle makes the same several turns you do. A face keeps turning up in places that have nothing in common. Someone knows when you leave work. Lesson 8 covers the devices: Bluetooth tags your phone can catch, and cellular GPS units it cannot. Lesson 7 covers the plate readers that can be misused by anyone with a login. The defensive goal here is narrow. Notice, keep a record, and get to safety. Never investigate the person yourself.

How to reduce it

Level 4 Hardened

If the threat is a person who knows you, safety planning comes before any tech step, because the tech steps are visible to the watcher. An advocate can help you decide what to change, in what order, and what to leave alone for now so the other person does not notice. The plan also covers what the tech cannot: where you will go, who knows, and what you do if the person shows up.

A separate identity is the core Level 4 tool. You keep an account, a number and a payment method that never touch your everyday ones, for one purpose: the support group, the activist work, the new address. It answers the re-identification threat only as well as you keep the joins closed. It does nothing against someone who already has your phone or your cloud password, which is why the safety plan comes first.

Physical awareness is the Level 4 habit that costs nothing but attention. Vary when you leave and which way you go, so a schedule is harder to learn. Tell someone your plans. If you think you are being followed while driving, do not drive home. Keep going to a police station or a busy, well-lit public place and call 911. Do not confront the person and do not follow them. Write down the date, time, place and a description, and the plate only if you can see it safely. That incident log is what a police report or protective order petition needs, and it is often what convinces others the pattern is real. What awareness cannot do is spot a tracker or a shared account; pair it with the checks in lesson 8 and the safety plan above.

Level 5 Hyper-vigilant

Level 5 tools answer the most capable threats: someone who can watch your phone's signals or your home network. They also fail quietly, so each one needs testing. A Faraday bag blocks radio to and from your own phone, so it answers live location and remote access while the phone is inside. It does nothing about what the phone recorded before it went in, or about a phone that was compromised already.

Tails is a free operating system you start from a USB stick in place of Windows or macOS. The project says it is a 1.9 GB download, needs a stick of 8 GB or more, works on most computers less than 10 years old, never writes to the hard disk, and sends everything through Tor's three relays. Its optional Persistent Storage is encrypted. It answers two threats: traces left behind on a shared computer, and a network that logs which sites you visit. It also says Tails cannot always protect you on a computer with malicious hardware, like keyloggers. Use it for one sensitive task at a time: download it only from tails.net, follow its install guide step by step, start the computer from the stick, do the task, and shut down. Never sign in to your everyday accounts inside Tails, since that links the session to you. Cost: a USB stick and a learning curve. Some sites block Tor, and everything runs slower.

The full ladder

Pictures, Numbers and Infographics

The arithmetic on Figure 1: 19,732 minus 10,937 is 8,795, and 8,795 divided by 10,937 is about 0.80. The first three quarters of FY 2026 add up to 52,081, already 94 percent of all of FY 2025.