What Data Does Facebook Collect When I’m Not Using Facebook, and Why?
If one takes out all of the defensive posturing (entire paragraph explaining that Twitter, LinkedIn, Amazon, and Google all do the same thing), and the intentionally simplified (cookies, which are identifiers that websites use to know if you’ve visited before), we are left with this:Facebook tracks virtually every website you visit, as well as usage data from many apps, even if you aren't logged in to facebook or don't have an account.  We use this data, and tie it to your identity whenever possible, so we can charge advertisers more money.