Bookmarked I Scanned the Websites I Visit with Blacklight, and It’s Horrifying. Now What? (

The Markup recently launched Blacklight, a free, instant privacy-inspection tool. Enter any website, and it reveals how you may be tracked when you visit the site, names the companies receiving your data, and explains what the trackers are doing—some of them watch your every mouse move and record your every keystroke. Trust us, it’s more than you’re expecting, raising the question: What can you do about it?

Aaron Sankin discusses Backlight, an instant privacy-inspection tool, and what it uncovers in regards to privacy on the web. Much of the focus is around cookies and the role that they serve in regards to tracking.

a cookie is a piece of data saved onto your device identifying you uniquely, which can only be read by whoever set it—whether that’s the site you’re visiting or a third-party marketing company that sets cookies on millions of sites and uses all that information to build profiles about us all. Some cookies can be useful—for instance, remembering you so you don’t have to sign in every time you visit your favorite site.

Some companies use cookies in concert with another tracker called a pixel, which is a small image or bit of code that sends information about your actions to whoever owns that pixel. If the owner of the pixel has also saved a cookie on your device, your actions on that page can be linked to everything in the profile that the company has already built on you—from your previous browsing history to purchases you made offline.

One of the hard things is that although you can clear and/or block cookies, this does not stop fingerprinting and session logging.

This is a topic that Doug Belshaw reflects upon in regards to his use of Firefox.