I have written in the past about porn spam on Facebook similar to what Myspace had but instead of showing up in your email, they post to Major Brand Fan Pages (examples are Doritos, Dunkin Donuts).
For years one of the issues holding back monetization of Social Media is the randomness of user uploaded content that could be good or bad to associate with. It goes beyond advertising. This is a really funny example via good intentions. This company used a Facebook Widget to showcase it’s Fans, but of course we can’t Choose our Fan’s on Facebook!