There is no anonymity on the Internet

There’s No Anonymity

Your information footprint on the Internet is like your body in the physical world: it represents your identity. Like seeing some part of your body, seeing some part of your information footprint — like the location of the device you’re posting from or the pattern of your language — may make it possible for someone to uniquely identify you even when there is no name or other explicit identifier attached.

Our Advice

Don’t do anything online that you wouldn’t do in public.

How It Works:

It is virtually impossible to remain anonymous on the Internet. As a consequence of the protocols used for Internet communication, some details of your device’s setup are communicated to your Internet service provider, and often to the site or service you are using. For example, your IP address is always transmitted, and when you’re browsing the web, your browser transmits information about the browser’s configuration to the website server. These details can be combined together to serve as a unique identifier.

Most web browsers have “private browsing” or “incognito” modes, but those names can be misleading; the sites and services you use can still identify you using IP address, browser configuration, and browsing history (via cookies), and can still track your activities on those sites. Even if you use a tool like an anonymization proxy to cover your IP address and the timestamps on your communications, uniquely identifiable information still leaks through: for example, your browser configuration, cookies, or the information you supply by submitting a query-by-example request.

Furthermore, data mining and inference techniques (see: You’re Leaving Footprints) can be used to match anonymized users to their real identities with a high degree of accuracy, including through language models, speaker identification, facial recognition, location correlation, activity modeling, and other retrieval techniques. But it doesn’t always require such specialized techniques; if there is even a single link between an online identity and your real self, somebody (or some bot) can submit a query using a single identifier (for example, a name, phone number, or email address) to a commercial data-broker service (such as or that aggregates data from many sources, and that service will give them a full personal profile, which can include home address, income level, job description, and other private information.

What Could Happen? Real-World Stories:

Petraeus and Broadwell Used Common E-mail Trick

Georgia Man Awarded $404,000 for Libelous Internet Postings

Suspected Anonymous Hacker Busted by FBI — Thanks to a Racy Photo

What You Can Do About It:

Choose What You Use:

  • Always assume you have less anonymity, and therefore less privacy, when you’re doing something electronically than you would if you were doing it non-electronically (e.g., credit cards vs. paper money, email vs. postal mail).
  • Only give out as much personal information as you have to. For example, before you enter any information in a form — online or even paper — or allow an app or service to access information about you (including your current location or your contacts), ask yourself what they need it for. If the company or service provider doesn’t need that information to provide the service you want, either:
    • Don’t give them the information;
    • Give them made-up information;* or
    • Choose some other way of getting that service.
  • This practice won’t make it impossible for others to track and identify you, but it will make it more difficult!
    • * When making up information, stay within legal bounds; it’s usually not a good idea to make up information on government forms, or when doing business with banks or other highly regulated services.

Customize the Technology:

  • Use tools that reduce websites’ ability to track your activities. (But remember that, despite claims, none of these tools can entirely stop tracking; no tool can address all potential tracking methods.)

How to Better Control Your Privacy — Guides:

Five Ways to Reduce Identity Tracking Online

Where to Learn More — Related Resources and Educational Tools:

There's No Anonymity

Our video explores how you can be identified online, and how to make it harder

Privacy in the Information Age: De-Identifying Your Classmates

A classroom activity from the Data Privacy Lab

How Unique Are You?

See how demographically unique you are

Find out what your browser reveals about itself — and you


See if your browser information is unique to you


Make yourself more difficult to identify and track

DuckDuckGo’s Guide

Use some of these tools to reduce browser tracking by websites

What Do You Think? Discussion Questions:

  1. Can you be anonymous on the Internet? Could people figure out who you were if you didn’t post using your real name?
  2. Can anyone be anonymous on the Internet?
  3. What are cookies and what do they do? Why do they matter?
  4. How do companies know who you are when you visit their websites?
  5. If you use Private Browsing/Incognito Mode/InPrivate to visit a website, will you be anonymous?
  6. Are there programs on your cell phone that track what you’re doing?
  7. How do your friends’ actions affect your anonymity?

What People Are Saying — News, Commentary, and Research:

They Know What You’re Shopping For

Researchers Expose Cunning Online Tracking Service That Can’t Be Dodged

An Analysis of Private Browsing Modes in Modern Browsers

There Is No Such Thing as Anonymous Online Tracking

How Unique Is Your Web Browser?

If There’s No Such Thing as Anonymous Data, Does 'Privacy' Just Mean 'Security'?

User Verification: Matching the Uploaders of Videos Across Accounts

Our New Resources for Teachers: "There's No Anonymity"