I do not have a Facebook account, though friends have uploaded pictures of me, and now my name comes up for tagging suggestions on other pictures. Facebook recognizes me, and knows my name, identifying me, even though I've never agreed to any ToS.

No doubt. Every load of their Like button and Comments widget on millions of sites is saved somewhere, building a nice graph of all the pages you ever visited from a particular IP and probably a cookie the widget saves.

Certainly. Facebook runs ads outside of just their own site, so they have to track as many folks as possible. Whether they're tracking PII of non FB users though is (hopefully) unlikely.

I would have asked this too (aka shadow profiles).

It's sad that it looks like the senators weren't even aware of this, or maybe some were but couldn't phrase in layman's terms.

He admitted that facebook used to collect your friends' data too, but they stopped doing that.