Annoyed by those pesky ads that keep following you online wherever you go? Join the club — we’re all tracked as we move across the web. Take a look at who tracks you, and what they know about you.

What is online tracking?

Online tracking is the practice of following, recording, storing, and repackaging your internet history for sale to third-parties. Whenever you visit a page, run a search, send an email, watch a video, or shop online — even if you’re just window-shopping — you can be sure someone, somewhere, is taking notes.

What do you mean, “someone”? Who’s tracking me online?

All the cool kids are doing it — from the FANGs of the world (that’s Facebook, Amazon, Netflix and Google for the AOBWs, or Acronym-Obsessed Blog Writers, out there) to your friendly neighborhood artisanal donut store website (probably).

No, really. Researchers at the University of Washington found that 75% of the world’s most popular websites use tracking tools — which include their own cookies and third-party trackers, collecting info on you all the time.

What do these online trackers know about me?

Imagine you were asked to come up with a list of 3,000 interesting facts about yourself. What sort of things would you write? 3,000 personal facts is a lot of personal facts. And yet, there’s a very good chance your list already exists.


There are marketing companies out there that own an average of 3,000 pieces of data about each of the 350 million people in their database — your location, the food and restaurants you like, your online habits, the sites you visit, the questions you ask Google, where you work… even your medical info and credit score.

Wow. So they know a lot. But why is that b—

Wait, I’m not finished. Websites can also collect information about your device, your operating system, browser version, fonts, screen resolution, color depth, timezone, what add-ons you use, whether you block cookies, whether you block ads…

Data companies and advertisers also know which articles you read and which ones you skip, which videos you watch, and which ones you stop after 5 seconds; which promotional emails you read, and which ones you send to your Trash folder without opening; what you like on Facebook, what you retweet, what you heart on Instagram.

Yes, that sounds bad — but why exactly is it bad for *me*?

When you put all these things together, as data miners do, you end up with your own unique online fingerprint — which immediately identifies you, with all your likes and dislikes and personal traits and neuroses (oh come on Brenda, we’ve all got them).

And that’s potentially very bad news, because once they know exactly who you are and what makes you tick, companies and advertisers can:

  • Spam you with finely-tuned, targeted ad campaigns that follow you around the web, attempting to trigger every latent subconscious desire of yours (oh come on Brenda, we’ve all got them) — or at the very least irritating you to death.
  • Potentially jack up their prices for you, because nice affluent location you got there, Brenda. For example.
  • Invade your privacy and chip away at your anonymity online, which nobody likes.

But nothing's all bad, is it? Not even —

Don’t say Hitler.

[long, uncomfortable pause]

No, I mean, online tracking isn’t all bad. For one thing, sometimes you want to go where everybody knows your name. So at least in theory, advertisers can offer you things and experiences you are actually interested in, rather than bombarding you with ads for, I don’t know, lawyers specializing in Canadian criminal pardons, which you obviously have no use for, Brenda.

Also, it keeps most of the internet free, because while companies and advertisers are busy charging each other for your data, they forget to charge you.

And that’s that on online tracking.

Liked this one? Try these:

What is a VPN? | Everything You Need to Know

The ultimate guide to Virtual Private Networks (VPNs), how they work and how they protect you. Learn why you shouldn't surf without one, and how to choose one.

Windows 10 Privacy | Is Windows 10 Spying on You?

Windows 10 Privacy: Everything you need to know to keep Windows 10 from spying on you

Why cleaning your browser makes it safer

Your browser collects more information than you, and that can be used for or against you. Ever wondered what the catch in your browser's cache was?

5 reasons to get an ad blocker

Ad blockers are more than just convenient ways of cleaning up the web. They also carry security, usability, and ethical challenges. Should you use one?