At Apophenia, danah boyd tells this great story about a recent renegade party:
Last night, i attended a renegade party buried in San Francisco. We could see the road from our location, but the road could not see us. When we saw cop car after cop car drive by, we knew it was over. But still, as they stopped, we crouched down, climbed trees, hid behind bushes. The officer climbed the hill with his flashlight, shining it on people. He got to the top where he realized there were at least 150 people there.Link
"Oh. My. God." was the only thing he could mutter. And he kept repeating it.
In response, someone jumped up and yelled "Surprise!" at which point everyone jumped into singing "Happy Birthday" to the officer. His eyes were wide with shock, jaw still slack...