Yes. Fighting back against gangs IS necessary. And we are stymied more by political correctness (see YouTube) than by lack of police officers. And thus we end up with "youths" much like those in Paris, uncontrolled by ANYONE.
Yaelle, you just don't quite seem to "get it". You keep thinking that this is a "gang". I'll bet every one of those punks know each other only a little bit. It was not an organized gang attack. It was some people of one race realizing that they outnumbered some people of another race, and took advantage of the numbers. Once it started, everyone else joined in.
You are trying desparately to avoid understanding something here. A lot of blacks in America hate white people for NO OTHER REASON than that they are white!!
Once you come to grips with that, what happened in your town will make a whole lot of sense. Till that happens, you are lost.