Glossary

A

Address Confidentiality Program

A state program that gives qualifying survivors a substitute address for government records and forwards their mail. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Data Brokers, Credit and Identity

Advertising ID

A resettable identifier your phone gives apps so ad networks can recognize the device across apps. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Your Phone: How It Leaks and How to Close It

Automatic content recognition (ACR)

Smart TV technology that tries to identify everything on your screen, including cable, antenna, streaming and disc content, for recommendations and ad targeting. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Home and Neighborhood

B

Basic and advanced border search

CBP's two kinds of device search. Basic is a manual look. Advanced means connecting equipment to copy or analyze, and needs reasonable suspicion or a national security concern plus senior manager approval. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Vehicles, Travel and Trackers

Botnet

A network of hijacked devices that someone controls remotely, often used to hide the source of attacks. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Home and Neighborhood

Browser fingerprinting

Identifying a device by combining many of its traits, such as browser version, screen size, fonts and time zone, into a profile that does not depend on cookies. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Browsing, Search and Email: How You Are Followed and How to Cut It

C

Cell-site location information

Time-stamped records a carrier keeps of which towers your phone connected to. It exists whether or not any app is running. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Your Phone: How It Leaks and How to Close It

Commercially available information

Data anyone can buy, such as broker files and app location feeds. Government agencies buy it too, often without a warrant. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: The Privacy Ladder: Who Is Watching and How Far to Go

Community Requests

Ring's system for local police and fire agencies to ask camera owners in an area to share video voluntarily. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Home and Neighborhood

Compartmentalization

Keeping separate identities on separate accounts, numbers, payment methods and devices so that one cannot be traced to another. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Hyper-Vigilance: When It Is Worth It and How to Do It Right

Consumer reporting agency

A company that compiles reports about people for decisions like credit, insurance or jobs. The Fair Credit Reporting Act lets you request your file. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Vehicles, Travel and Trackers

Counter-surveillance

In this guide: lawful steps you take to limit how much others can collect about you. It never includes interfering with other people's devices or with lawful process. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: The Privacy Ladder: Who Is Watching and How Far to Go

Credit freeze

A block on your credit file at one bureau so lenders cannot pull it to open new accounts until you lift it. Free under federal law. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Data Brokers, Credit and Identity

D

Data broker

A company that collects personal information from many sources, builds profiles, and sells or licenses them to others. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: The Privacy Ladder: Who Is Watching and How Far to Go

A company that collects personal information from public records, purchases and other sources, combines it, and sells or licenses it to others. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Data Brokers, Credit and Identity

DeFlock

An open-source, crowd-sourced map of license plate reader cameras in the United States. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Out in Public: Plate Readers, Face Scans, Events and Protests

Detecting Unwanted Location Trackers (DULT)

The Apple and Google industry specification, now in an IETF working group, that lets iPhones and Android phones warn about each other's compatible trackers. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Vehicles, Travel and Trackers

DNS

The system that turns a site name into an internet address. Unencrypted lookups show your network and ISP every site you visit. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Browsing, Search and Email: How You Are Followed and How to Cut It

E

End-of-life router

A router its maker no longer supports with security updates, so known holes stay open. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Home and Neighborhood

End-to-end encryption

Encryption where only the devices in the conversation hold the keys, so the company carrying the message cannot read it. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Messaging and Calls

F

Facial comparison (one-to-one)

A camera checks whether your live face matches the photo on the ID you just handed over. TSA uses this at checkpoints with CAT-2 scanners. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Out in Public: Plate Readers, Face Scans, Events and Protests

Faraday bag

A pouch lined with conductive material that blocks radio signals, so a phone inside cannot reach towers, Wi-Fi or Bluetooth. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Your Phone: How It Leaks and How to Close It

A pouch lined with conductive fabric that blocks radio signals to and from a device inside it. It blocks only your own device, unlike an illegal jammer, which broadcasts interference. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Hyper-Vigilance: When It Is Worth It and How to Do It Right

Fraud alert

A note on your credit file telling lenders to verify your identity before opening credit. One request reaches all three bureaus. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Data Brokers, Credit and Identity

G

Geofence warrant

A warrant asking a company for every device its records place inside a drawn area during a set time, then narrowing that list to a few accounts. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Out in Public: Plate Readers, Face Scans, Events and Protests

Guest network

A second Wi-Fi network on your router with its own name and password, kept apart from your main network. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Home and Neighborhood

J

Jammer

A device that blocks or interferes with radio signals such as cell, GPS or police radar. Illegal for the public to use, sell or market under federal law. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Out in Public: Plate Readers, Face Scans, Events and Protests

L

Location aggregator

A middleman company that bought access to carrier location data and resold it to other businesses. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Messaging and Calls

Lockdown Mode

An extreme iPhone, iPad and Mac setting that shuts off features often used by sophisticated spyware. Android's closest match is Advanced Protection, introduced with Android 16. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Your Phone: How It Leaks and How to Close It

M

Metadata

Everything about a message or call except its content: who, when, how long, and often where. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Messaging and Calls

N

National lookup

A plate reader search that reaches cameras owned by other agencies that have agreed to share, sometimes thousands of networks in many states at once. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Out in Public: Plate Readers, Face Scans, Events and Protests

O

One-party consent

A rule letting a person record a conversation if at least one participant agrees. Idaho follows it. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Home and Neighborhood

One-to-many matching

Face recognition that compares one face against a whole watchlist. Error-prone when the list is built from poor photos. TSA's checkpoint check is one-to-one instead. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Out in Public: Plate Readers, Face Scans, Events and Protests

P

People-search site

A website that compiles public records and purchased data into profiles listing addresses, phone numbers and relatives. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Data Brokers, Credit and Identity

R

RCS

Rich Communication Services, the carrier messaging standard that replaces SMS on many phones. Some RCS chats are end-to-end encrypted; SMS never is. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Messaging and Calls

Re-identification

Matching supposedly anonymous data back to a named person by combining it with other facts, such as a ZIP code, a birth date or public reviews. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Hyper-Vigilance: When It Is Worth It and How to Do It Right

Real-time bidding

The split-second auction that decides which ad you see. Your app or browser sends a bid request with details about you and your device to many possible buyers. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: The Privacy Ladder: Who Is Watching and How Far to Go

Registration Lock

A Signal setting that requires your Signal PIN before anyone can register your phone number on a new device. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Messaging and Calls

S

SDK

Software development kit: a package of outside code an app developer builds into an app. Some SDKs collect location and send it to the company that made them. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Your Phone: How It Leaks and How to Close It

Significant Locations & Routes

Apple's on-device record of places you go often, how often and when, and the routes you take. Apple says it syncs with end-to-end encryption. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Your Phone: How It Leaks and How to Close It

SIM swap

A fraud where a criminal gets your carrier to move your phone number to a SIM card they control, so your calls and text codes go to them. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Messaging and Calls

Stalkerware

Software someone installs on your device without your knowledge to track location, messages, calls or browsing. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: The Privacy Ladder: Who Is Watching and How Far to Go

Software secretly installed on someone's phone to monitor messages, location or activity. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Hyper-Vigilance: When It Is Worth It and How to Do It Right

Synthetic identity

A fake person built from a real piece of data, often a Social Security number, combined with an invented name and birth date. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Data Brokers, Credit and Identity

T

Tails

A free operating system that runs from a USB stick, leaves no trace on the computer, and sends all internet traffic through Tor. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Hyper-Vigilance: When It Is Worth It and How to Do It Right

Telematics

Data a connected car sends home over its own cellular modem about where it is and how it is driven. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Vehicles, Travel and Trackers

Third-party cookie

A small file set by a site other than the one you are visiting, often an ad or tracking company embedded in the page. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Browsing, Search and Email: How You Are Followed and How to Cut It

Threat model

Your answers to what you are protecting, from whom, how likely and how bad a loss would be, and how much effort you will spend. EFF calls this a security plan. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: The Privacy Ladder: Who Is Watching and How Far to Go

A short, honest answer to who might want your information, what they could reach, and what happens if they get it. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Hyper-Vigilance: When It Is Worth It and How to Do It Right

Tor Browser

A free browser that sends traffic through several volunteer relays so no single relay knows both who you are and where you are going. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Browsing, Search and Email: How You Are Followed and How to Cut It

Tracking pixel

A tiny image in an email that tells the sender when, and sometimes where, you opened it. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Browsing, Search and Email: How You Are Followed and How to Cut It

U

Unknown tracker alert

A phone notification that someone else's Bluetooth tracking tag appears to be moving with you. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Vehicles, Travel and Trackers

V

VPN

A service that tunnels your traffic to its own server, so sites see the VPN's address and your ISP sees only the tunnel. The VPN company sees everything. Guarding Your Privacy Online and IRL: Counter-Surveillance and Privacy Tools from the Mundane to Hyper-Vigilance: Browsing, Search and Email: How You Are Followed and How to Cut It