Facebook announced this week that they will begin republishing user information in ads in a feature called "sponsored stories." They'll be using your likes and check-ins with sponsors in ads that your friends will see.
The controversy (doesn't it seem like there always has to be controversy with a Facebook announcement?) is that you can't opt out. Facebook's defense is that they're not telling anyone anything they wouldn't have seen anyway. If you check in at Cora's Cafe, that shows up in your friends' news feed in accordance with the level of privacy you've specified. It may also now appear in an ad for Cora's Cafe on the right of the page (where ads already are). The logic goes that if you like a business (in the Facebook sense of the word), you're publicly showing support for them and wouldn't object to having your appreciation used to benefit them.
Several people have noted that it seems like a watered down spin on Beacon, which Facebook discontinued in 2009 after a lawsuit.
Facebook's Statement of Rights and Responsibilities says that "you own all of the content and information you post on Facebook, and you can control how it is shared through your privacy and application settings." I assume Facebook would contend that because they're sharing things only to people who would see the same information in their news feeds, your privacy settings also apply to the sponsored stories. I also assume that many users would disagree--that being involuntarily used as a corporate spokesperson should involve its own privacy setting.
How do you feel about sponsored stories? A reasonable revenue stream for Facebook and appropriate extension of its abilities? Or another violation of its users' trust--what little might be left?