How would they do this if you never visit the site or download the app? If you're referring to the use of a pixel, compared to the full-fledge use of cookies used by other ad networks (the Gizmodo article from yesterday itself noticeably had ads all they way down the page based on sites I'd recently visited), surely that alone doesn't make FB evil relative to other advertisers?
what about when all your friends use Facebook? Then you are going to be forced into a situation where you either use Facebook or stay disconnected from you friends.
Why are you forced to use Facebook or be disconnected from your friends? You still have texts, email, Twitter and phones. I know a few people (admittedly not a lot) that refuse to use Facebook. They complain occasionally because they believe they are missing out on seeing photos or something, but nothing to the point where they are in the dark. I think the use of Facebook is a convenience and each person has to weigh their values against what they know Facebook does. But let's not elevate what Facebook does beyond the level of displaying ads for money and crossing ethical boundaries in some instances about what data they use to target those ads. Based on some comments you'd think they were proactively trying to destroy the world.