They're not volunteers.
When we moved here, we considered buying a foreclosure that would have been on the border street, and thus in the SRA. It required so much work, new floors and walls, it was built many decades ago, and it was a tiny structure, with tiny rooms, don't remember the square footage of the whole place, but maybe 800-900 square feet. We decided to not bid on it due to the renovation work required to make it livable. I think it sold at auction for $43K or thereabouts (in 1999), but I'm going from a rather poor memory. What I'm trying to say is these border areas are places where rather poor folks are likely to live, given that this is Southern California.
Travel another 1/4 mile north, and there's a canyon, and the canyon rim properties are generally sprawling estates, clearly those of folks of more means. And, some of those places on the canyon rim burned in the last decade in some pretty devastating fires, though the fire departments did a great job at saving most of them.
(Now that I write this out, I'm gonna have to direct all the solicitors we get 1/4 mile north. Sorry, you're at the wrong house, but I know where you need to go! I keep forgetting to do that.)
To me, it's just sad that our overall tax load is so regressive, and clearly getting moreso, while 1%er folks like Romney (Governor Feefee) prattle on about the 47% freeloaders.