I'm thinking that it's very easy to combat gangs, drug-dealing, and all the rest.
You simply get into an old car, and start driving around slowly while a passenger runs a video camera. After 2-3 passes, the drug dealers close up shop, the ho's go away, and the word is definitely out.
On several occasions, I've "confronted" local kids that I knew were dealing drugs. I told them that I'd heard that (gasp!) drugs were being sold, and asked them if they knew anything about that. They always said "no", started calling me "sir" (a dead giveaway of guilt), and we agreed that they'd call me if they heard of anything. It always took care of the problem.
The key here is that the neigbors allow it, usually because it's their kids (and tenants!) doing the bad stuff. I've seen dozens of cases, some locally, where the residents fight the cops in everything they do, then have the gall to b*tch about the violence. Go figure.
LOL, I'm not sure where you're employing those tactics, but if it's in the Los Angeles area, I'd suggest you think twice about what you're doing.
Gangs out here have some great initiations. A lot of the drive-by or freeway shootings are the result of prospective members meeting the requirements.
If you run into some of the Salvadoran gangs, you won't have to do a darned thing to risk your life. And if you challenge their turf, your family will be putting daisies on the dirt above you in the near future.