Unknownsoldier - It could be that gang-bangers in the UK are more scary, but I really wouldn't know about that one. I can tell you that at least in my neck of the woods, some of the communities have taken an active stance in dealing with the bad guys.
One incident in particular I remember pretty well...One of the gangs from the next city over attempted to expand their claimed territory, and decided to start off with the a block occupied by a restaurant, liquor store, a white hen, and a few other mom and pop establishments. When the restaurant noticed that they were getting tagged and patron's vehicles were being stolen/vandalized, they decided to hire a small private security force, supplement them with off-duty police officers, and encourage uniformed police to bring their squad car by and pop in for free lunch. Things got very quiet very quickly.
Tolduonce - I like my idea better. If there IS someone out there and he DOES have some ill will towards me or my neighbor, I'll make sure he doesn't get the chance to act on it.
Gang-bangers in the UK has totally different connotations....