We know Zuck was close to Adam D'Angelo. They went to High School together and even built the digital music software that first igniting Zuckerberg's entrepreneurial imagination back in his teens. Cohler was employee number five at Facebook — there when the company was one room big. Zuck recruited Hammerbacher, whom he knew from Harvard, to join the company from a presumably well-paying gig at Bear Stearns. With all his friends leaving, oon Zuckerberg won't have any Woz- or Allen-like buddy at the company.

Cofounder Chris Hughes left a while ago to work on Barack Obama's presidential campaign. Another cofounder, Dustin Moskovitz, has been rumored to be on the outs with Zuckerberg, though Moskovitz attributes any disputes to normal friction between founders. And now D'Angelo — though not a founder, one of the small group who helped Facebook relocate from Zuckerberg's dorm room to Palo Alto — is gone, too. He may be leaving for his own reasons, but his departure is a sign that the company is fitfully growing up.

"While this change definitely curtails the ability of low quality apps to spread, it doesn't allow high quality apps enough channel access to thrive," Inside Facebook's Justin Smith writes. High quality? Why doesn't Zuckerberg just get rid of every app besides Scrabulous? That seems easier.

Chamath Palihapitiya, the former AOL executive, now heads up marketing; having criticized Silicon Valley's white-male old boys' club, Palihapitiya must surely be pleased with Van Natta's comeuppance. Matt Cohler, the early LinkedIn employee cofounderwho jumped to Facebook some time ago, is now in charge of "business operations" and strategy. Gideon Yu, the recently hired CFO, is now free to fib about Facebook's finances, as he did as YouTube's CFO after that company was acquired by Google. And close Zuckerberg associates Dustin Moskovitz and Adam D'Angelo now have tighter reins on the company's products and technology.

But Zuckerberg could be setting himself up for a fall. By elevating Van Natta's rivals, he's going to find himself spending time on personality conflicts, infighting, and turf warfare instead of tending to the needs of his beloved users. Palihapitiya, Cohler, and Van Natta, for example, are, by their titles, charged with Facebook's "operations." The more Zuckerberg's executives spar over fields of authority, the less attention they'll pay to business. Zuckerberg has asserted his power — at the cost, potentially, of his abiity to get things done.