What would you do if you saw someone being robbed? Would you chase the robber? What would you do if you managed to catch him? Would you hit him with all your strength?
Check out this video on YouTube.
If I was there and if I’m a man, I’ll serve him with my fists and kicks. Anyway, it’s just an IF. However, I don’t encourage you to do this if you don’t have 100% confident. Your personal safety is the first. Think well before you do it. Don’t risk your life because of this. It doesn’t worth it.
Try seek for others help or call the police when you spot this kind of incident. If you’re with your gang, you might try to catch him. But, remember also: safety first. Do not risk yours and your friends’ lives.