Oakland is a very dangerous place with or without the gangs. There's a whole lot of crime goin on there. I've had the misfortune to be there numerous times over the last few years.
About ten years ago I had to drive over there from San Francisco to pick my husband up at the Oakland airport ... at night time, took the wrong turn off and had to drive city streets to the airport, stopped at a service station for instructions and was stunned to see they had police guards at local gas stations after dark... Jerry Brown did nothing as mayor to make Oakland better, if anything it got worse (from my viewpoint) under him.