It really depends on the situation. In this case, my tactic worked. I calmly told the man that there were children on the bus, and that he should tone down his conversation. Then I pulled out my phone to take his picture, but he covered his face and got off at the next stop. I wonder if he was worried about an encounter with police. Next time I'll take a picture first.

Yet another instance where life logging would have been useful: I was walking home this evening and someone in a car blasted me with an air horn. It's been about an hour since the incident. Both my ears feel like they are plugged and I hear ringing in my right ear. I got the car's make and model, but I was in too much pain to think about looking for the plate. Life logging probably would have caught the perpetrator.