Earlier quoted context omitted.
> How would they do this if you never visit the site or download the app? Your friends install the app on their device. They provide access to their contacts. FB slurps in all of that data. For every person in the user's contacts, FB compares that info to their records. They update connections where found, and start new records when not found. So they now know your name/email/phone number/physical address info depend…
That’s not tracking web activity though. Also, why is google given a pass here? They use info gathered from my emails all over the place and that surely has more sensitive data than my Facebook account. What about amazon who has been reported to sell your purchasing data without your explicit consent to advertisers?
I'm definitely not giving Google a pass. I just didn't mention them ;-) Google Analytics, Fonts, whatever are just as bad, to me. I as an unsuspecting web user have my browser tracked from web developers using some free tools. I have no idea that it is occurring as a viewer. If a website puts in FB's like buttons, it is visible to me, and being in the know, I understand the repercussions of that site's decision. GA, Fonts, etc, are completely hidden from view. This is why I've used NoScript/Ghostery/etc throughout the years. It started with ads, but now I'm more concerned about these types of scripts.