Next time you type your skin rash symptoms into WebMD, brace yourself for a barrage of ointment ads.
According to Blacklight, a new tool from the nonprofit tech site The Markup, dozens of marketing companies track your WebMD visits.
And don’t think health websites are alone here: Blacklight lets you see exactly what info all sorts of websites have on you.
How does it actually work?
You have to go to the tool’s homepage and enter a link.
The system then reads the page for “trackers.” That means info about you, your keystrokes, and your searches that advertisers and other companies are compiling.
Should I be worried about this?
A lot of what Blacklight reveals is obvious. As Recode points out, you probably won’t be surprised to hear that news sites have a couple dozen ad companies tracking you.
There are definite shades of gray, though. Breitbart, for instance, uses a tool called “canvas fingerprinting” that keeps tabs even if you turn off your cookies. Airbnb’s website does the same.
And then there are the bizarre cases: Even government COVID-19 informational pages apparently forward your info on to ad-tech companies.