Top of Drudge Report right now:
pjmedia.com/lifestyle/shock-facebook-tracking-even-youre-not-facebook/
Yes, but I can't remember where I read about it recently, so unfortunately I can't provide sauce, this is all from memory.
It's ultimately about AI. Creating a fake "you." Imagine, they know absolutely every fucking little detail about every aspect of your life. They know how you write grammatically, and what your voice sounds like. So one day they send an email from your account, threatening to kill someone, or admitting you molested the neighbor-kid, or offering to work with terrorists, or selling confidential info from your place of business. How do you claim it wasn't you who sent it? Law enforcement can line up a string of forensics-experts who will testify that it's your style of writing, etc. And then they've got you. Like a Twilight Zone episode.
There was a lot more to it, but technically it went over my head. If I can find it I'll post it.