Facebook Keynote at f8 Pits Zuckerberg vs. Zuckerberg [VIDEO] Will the real Mark Zuckerberg please stand up? Wait a minute -- that's Saturday Night Live's Andy Samberg standing in for the Facebook CEO at the f8 keynote, all in good fun. Our favorite moment's at 5:00: Samberg's "new" Facebook feature for "I'm not really friends with these people." More F8 Coverage: Prepare Yourselves: Facebook To B