https://boingboing.net/2017/11/08/involuntary-profiling.html
FB goes so far as to buy your data from others, which is why I block all trackers. I'm sure I still leak data to FB, even though I never joined, and never will.
They know which IP addresses you connect to. Many of those host large numbers of websites.
> what types of data you pass to them
What do you mean with 'what types of data'? They can't access the headers of encrypted traffic.
> every single DNS lookup you make
Yes, that's true. And you can cache those locally.
> etc. Sorry, but this is FAR more intrusive than Facebook, which you CLAIM has lots of data on you even if you don't use their service.
Shadow profiles are a thing.
> It's harder to avoid Google than it is to avoid Facebook, but again, it's doable.
It's just about impossible. Every other email you send ends up in a gmail inbox. So even if you don't use their services at all your data still ends up with them. Even if you don't have a smartphone enough people around you will have them that your social graph will end up with Google anyway. And so on.