I do not see how this unimportant enough for them to say that.. These things can lead to murder if they ever go too far.. They checking for mobile phones in the area could go a long way in narrowing it down(they invade our privacy anyway), once they have suspects, i am sure they can proof too.

GooFy does have a point, since they initiated, defending yourself is very much an option. But i have never been in such situation, though. I did get stopped by a group near a railroad passing, and got threatened there, but that never got violent. I basically bluffed knowing that most of the group was not interested.

Maybe you are blowing a single experience out of proportions? I am sure most people are mostly non-violent, or vent it in sports. Otherwise, i could not explain how i have to deal with violence so little. Maybe violence is a bigger problem in your area though.