Your information footprint is larger than you think

You’re Leaving Footprints

Your information footprint is not just what you intentionally post online. It consists of all of the information that you post or that others post about you, the hidden data attached to those posts by the services you use, the record of your online activities, and also the inferences that can be drawn from putting that collective information together.

Our Advice

Periodically check your privacy settings and update them, if possible, to limit unintentional information sharing.

How It Works:

It can be surprising to realize how much hidden information about your activities is stored and transferred in modern systems. To begin with, every Internet connection automatically transmits the sender’s IP address along with whatever information the user sends — whether the user is sending an email message or just “sending” a request to view a webpage. In other words, every time you visit a website, you leave a trace! Websites and apps store this and other data about users’ behavior — in some cases, even very detailed information like where your mouse hovers or how your finger moves on the screen.

In addition, many apps and devices (such as TVs, tablets, and mobile phones) exchange information, often without the user knowing. Mobile apps often communicate the device’s location, as well as configuration information hidden from the user. Multimedia content, such as images, sound, and video, often contains metadata that is not typically visible without a specialized reader. For example, EXIF is one common metadata format for images (like JPEG or TIFF files) that can contain unique identifiers like the location where the picture was taken, the time, and even the serial number of the camera.

Even when you’re not using the Internet directly, your everyday activities generate data. (See: You Can’t Escape) Going to the doctor, making a purchase with a credit card, or even turning on the TV — all of these things generate bits of data that usually end up in online systems, making your information footprint bigger.

Finally, data collected about someone from many sources, including information they post intentionally, metadata attached to those posts, and information provided by others, can be combined to infer even more information about that person. For example, a tweet saying you’re on vacation, the name in your Twitter profile, and a public record linking that name to the address of the house you own, could be used by a criminal to identify a good target for a robbery. Data mining techniques based on statistics and mathematical logic can be used to find patterns and draw these kinds of inferences on a large scale.

What Could Happen? Real-World Stories:

Burger King Employee Stands on Lettuce: Busted by Internet

Betrayed by Metadata: John McAfee Admits He’s Really in Guatemala

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

What You Can Do About It:

Customize the Technology:

  • Check your privacy settings on your mobile apps, computer software, and online accounts. The default is often to share every type of information with the widest audience possible; you have to “opt out” if you don’t want to share. Some settings that can typically be turned off:
    • Location services, which provide GPS information about your current location to and through the apps you use on a device. (Some location-related apps, like maps, do need location information for some functions.)
    • Metadata (such as EXIF) in images (except when you need the data for sorting or image editing); many sites do this automatically, while others make it optional. You can also use an EXIF Remover tool to remove metadata from images before you upload or email them, and some image-file formats, like PNG, don’t contain EXIF data in the first place.
    • Sharing contact information with third parties.

Communicate About Preferences:

  • Check your privacy status with companies. Banks, insurance providers, hospitals, and other companies are often legally bound to let you opt out of at least some types of data sharing.

Choose What You Use:

How to Better Control Your Privacy — Guides:

How to Disable Mobile Geotagging

Four Privacy Settings You Should Enable in iOS 7 (for Apple)

How to Disable Facebook Places Location Tracking

Five Ways to Reduce Identity Tracking Online

New iPhone or iPad? Change These iOS 8 Privacy Settings Immediately

Where to Learn More — Related Resources and Educational Tools:

Ready or Not?

Our app that shows how people could use social-media posts to find you

EXIF Placer

Our tool that shows how EXIF metadata reveals where a photo was taken

Hot on Your Trail: Privacy, Your Data, and Who Has Access to It

A video about what kind of information is tracked and who is tracking it

DuckDuckGo’s Guide

Use some of these tools to reduce browser tracking by websites

Sharing Information: A Day in Your Life

An introductory video about types of information gathered and sold

You're Leaving Footprints

Our video explains what’s in an information footprint and what you can do to reduce your exposure

My Teenagers Love Using Location Apps on Their Phones ... Is That safe?

Guidance for parents from Commonsense Media

Privacy in the Information Age: De-Identifying Your Classmates

A classroom activity from the Data Privacy Lab

Lightbeam Firefox Add-On

A tool that shows which third parties are tracking you at the sites you visit

Tor

Make yourself more difficult to identify and track

What Do You Think? Discussion Questions:

  1. What is an information footprint? What’s in it?
  2. How would you measure the size of your information footprint?
  3. Where does all this information live?
  4. Who “owns” the information?
  5. What actions make your information footprint bigger?
  6. Can you make your information footprint smaller?
  7. How do your privacy settings on different websites affect your information footprint?
  8. How do your friends’ actions affect your information footprint?
  9. Does the size of your information footprint affect the power others have over you?
  10. Can websites and online services make copies of your information without asking you? How do you know if they’ve duplicated it?
  11. What is metadata, and what is it used for? What can it be used for?
  12. Could someone use information about you online to figure out things about you that aren’t online?

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

Amazing Mind Reader Reveals His 'Gift'

Cyber-casing: Did You Just Geo-tag Your Car Keys to a Criminal?

Cybercasing the Joint: On the Privacy Implications of Geotagging

Blown to Bits, Ch. 2 -- Naked in the Sunlight: Privacy Lost, Privacy Abandoned

Eyes Over Compton: How Police Spied on a Whole City

Google Defends Way It Gets Phone Data

Social Media Users May Be Revealing Too Much About Location

When 'Smart Homes' Get Hacked

The Growing Art of Data Dodging

Volunteers in Metadata Study Called Gun Stores, Strip Clubs, and More

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

Your Digital Trail, and How It Can Be Used Against You

Our New Resources for Teachers: "You're Leaving Footprints"