We all have instant-message conversations we wish we could take back. (Well, those of us under the age of 25 at least.) But not all of us have the notoriety of Mark Zuckerberg. Zuckerberg found himself on the defensive after, shall we say, apolitical chat conversations surfaced in May, in which the then-youthful Facebook founder describes his users as "dumb f***s." A big uh-oh, especially considering the timing — right in the middle of the company's privacy brouhaha over displaying user's interests.