The Ways in Which Facebook Builds User Data Profiles for Targeted Advertising ⇥ t.co

Joanna Stern, Wall Street Journal:

A conspiracy theory has spread among Facebook and Instagram users: The company is tapping our microphones to target ads. It’s not.

[…]

I believe them, but for another reason: Facebook is now so good at watching what we do online — and even offline, wandering around the physical world — it doesn’t need to hear us. After digging into the various bits of info Facebook and its advertisers collect and the bits I’ve actually handed over myself, I can now explain why I got each of those eerily relevant ads. (Facebook ads themselves offer limited explanations when you click “Why am I seeing this?”)

Advertising is an important staple of the free internet, but the companies buying and selling ads are turning into stalkers. We need to understand what they’re doing, and what we can — or can’t — do to limit them.

Think about how quickly we’ve accepted this as the new normal, and why. Do we really prefer highly-specific advertising, as Facebook and Google say we do, or is it simply very creepy? Even if you don’t have a Facebook or Google account, you’re using Safari — which limits ad tracking by default — and have all sorts of silly settings to limit your exposure to trackers, there are still an extraordinary number of ways that your information can be acquired for highly-targeted advertising, almost always without your explicit permission.