In 2001 I was biking Market Street to downtown SFO. Agro Biker, several hundred feet in front of me, was heading straight through a green light. That didn't stop Stupid SUV from rushing to turn right, nearly causing Agro Biker to t-bone.

In response Agro calmly reached into his messenger bag, pulled out what I can only describe as a smoke grenade, and lobbed it at Stupid SUV's rear window. Direct hit. Shock and awe filled the streets!