Here’s the story SFZ mentioned earlier…
Protesters Throw Bricks and Bibles at Police in San Francisco

Occupy San Francisco’s “Day of Action” turned violent Friday night when protesters occupied an abandoned hotel and began throwing objects at police officers from the roof, police said.
“Once they gained access [to the hotel], some of them made it to the top of the roof and they then began to throw bibles down at the officers,” San Francisco Police Department spokesman Carlos Manfredi said.
“One of officers was struck with a brick to the chest and one of our lieutenants was struck in the hand with an object and may have damaged or even broken his hand,” he said.