We've all heard of flash mobs before -- groups of people who spontaneously assemble in a public place to perform a seemingly pointless act. But did you know that pillow fights are also part of flash mob culture?

It's true! The largest recorded flash mob pillow fight took place on March 22, 2008, during which people in 25 cities around the globe participated.

While this pillow fight flash mob in San Jose isn't nearly as big, it sure looks mighty entertaining. After a call for participants went out over Facebook and Twitter, hundreds of people -- including several in Santa suits and one man wearing a horse mask -- converged on San Jose City Hall this past Sunday and beat the heck out of each other with pillows.

Needless to say, feathers were everywhere.

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