When Facebook CEO Mark Zuckerberg was asked pointed questions about privacy breaches at last week's D8 Conference, he started sweating so much he had to take off his sweatshirt. Inside, was a strange symbol. What does it mean?

At SFWeekly, Alexia Tsotsis explains the symbol's hidden meaning:

• The bi-directional arrows indicate that each part generates inbound and outbound sharing;

• The labels on the arrows — GRAPH, here represented by the "friend requests" icon, STREAM, represented by the "messages" icon and PLATFORM, represented by the "notifications" icon — represent the three prongs of Facebook's strategy for 2010, as revealed at F8 conference;

• The blue ring is the interface or Facebook's wall around user data — 
the permeability of which remains a major point of controversy;

• The motto on the upper half of the blue ring,"Making the world more open and connected" is, according to Zuckerberg, Facebook's obviously unofficial "Mission Statement."

Oh, also there is a SECRET HIDDEN STAR OF DAVID. And Beelzebub's face. (via Daily Intel)

Update: Commenter BullfightsOnAcid points out that you can now buy this sweatshirt on eBay! It is the "same exact one" worn by Mark Zuckerberg. Who knows if that means it's actually the one he wore, or if it's just the same model. [TechCrunch]

Here are All Things Digital's Kara Swisher and Walter Mossberg examining the hidden symbol on stage, after a sweaty Zuck took it off:

(Pic via Esthr's Flickr)