My impression is that the Chinese mafia is still pretty strong in San Francisco. They own, directly or indirectly, a fair amount of real estate. And I presume they're behind a fair amount of grey market trade, as well as most of the brothels. I personally know of at least one business front on Clement St that was and is (AFAICT) still a meeting house. I used to live nearby, noticed the odd comings-and-goings, and confirmed my suspicions with a couple of the neighboring merchants. I distinctly remember one merchant, after asking what the deal was with the place across the street, leaning in close and asking me, "do you really want to know?". I said, "Well... I assume it's the mafia". He looked straight at me and silently nodded.

Anyhow, it seems to me that they're an established institution with a strong incentive to avoid violence or to participate in activities (e.g. drugs) that beget violence or unwanted attention. And City Hall and the police are comfortable maintaining the status quo, even if it means turning a blind eye to various activities on a regular basis. At the same time I assume that the other gangs around the city know their place in the pecking order and stay away from the predominately Chinese neighborhoods.

And maybe that's why the Shrimp Boy thing became so violent--he was an existential threat to the order and he knew he either had to go nuclear or go home. But he was always destined to lose. The media labeled him a "kingpin" but given the huge amount of money controlled by the Chinese mafia in the city, and the penny-ante schemes he ran that recently came to light, he seems to have remained on the fringes.

The Russian mafia also has a presence here. The Outer Richmond has one of the oldest Russian communities in the country. Like the Chinese mafia they seem to fit into the established political order, are plugged into the global grey market, and likewise have an interest in avoiding drawing attention to themselves.

Then there are the Irish. Hardly the same thing, but it's my understanding that for a long time the San Francisco Irish community was a standout supporter of Sinn Fein, maybe even in the same league as Boston in terms of political and financial support. I don't even think that was hidden. You can go to Ireland's 32 on Geary St and see publicity photographs of Sinn Fein leaders meeting with city officials.

Anyhow, I guess my point is that one of the safest places to live in the city is the Richmond District, where the Chinese mafia, Russian mafia, and whatever loose organization the Irish have going (construction?) seem to keep the riff-raff away, or at least organized riff-raff. I remember reading some stories 10 or so years ago about violence (muggings, break-ins) attributed to a nascent Vietnamese gang in the Richmond District, but that seemed to quickly disappear almost overnight. I doubt that was coincidental.