Does someone have a bounty on the head of 23-year-old Facebook founder Mark Zuckerberg? According to a source familiar with the matter, Zuck has recently brought in hired muscle to stand watch at his office in Palo Alto and even had a phalanx of bodyguards on call at the speech he made on November 6 at the annual Foursquare Conference regarding Facebook's new advertising initiative. "They were there to watch over Mark," says the source. "He's been getting lots of death threats of late."

In a comment straight out of Catch-22, a Facebook spokeswoman said that she had neither heard of any such death threats, nor would she comment if she had. "That's Mark's private life," she added.

There's no shortage of suspects. The founders of ConnectU, miffed that their lawsuit accusing Zuck of code theft will likely prove fruitless? Advertisers, pissed off that they've thrown bundles of cash at a website that is "consistently the worst-performing site" in terms of return on dollars invested? Myriad people who just think the guy is kind of a herb? The possibilities are endless!