Facebook sells absolutely zero user data to advertisers, full stop. It allows advertisers to target users by profile fields; if you think this somehow equates to selling user data, then Google's AdSense product, with the exact same feature set, must also equate to doing so.

How does Google target ads at you without a social network? By sticking a pixel on half the web and watching where you surf, and running Bayes' rule on the results to determine that you're 25-30, male, live in California, are interested in punk rock, etc.

To cut to the chase, let's make this interesting: I'll give you $10k, US. Go "buy user data" from Facebook. For example: I'll put a friends-only privacy field on my profile. If you can tell me the contents of that field in a week, I'll give you another $10k. If you can't, please return $20k to me, and stop repeating this absurd meme.