I'm particularly annoyed by the new arm-twisting (blackmailing?) going on in software circles where you're now required to "like" a piece of software on Facebook (or Tweet it) before you're allowed to download a lite or evaluation copy.
I'm surprised Facebook even allows that since it devalues the whole "liking" process.
Same goes for only being allowed to join something via your Facebook account. One place even had this helpful bit of information if you didn't have a Facebook account and still wanted to join. It said: Still want to become a member but don't have a Facebook account? Click here