Poetic Terrorism
Here's my idea. I honestly hope to follow through on this plan sometime in the near future.
Setting: San Francisco's Financial District.
Have a professional-looking friend (business suite, tie, suitcase) stand on the side of the street. He should be very engrossed in the business conversation he is having on his cell phone. Then, a van (or any real vehicle. Vans just look more ominous) comes around the corner and 2-4 people jump out, preferably with their faces covered. They grab the business man, pin him to the ground and "clip" a big red tag on his ear. They then release their new specimen into the wild once again and climb back into the van and drive away. Make sure there are lots of witnesses.
Should be good times.