alarms

Do car alarms do any good at all? My car has one, and it gives me a very small discount on my insurance, so it's good for me in that sense. (But there are very short drivers getting insurance discounts for having air bags in their cars, even though the air bags are actively dangerous to them. So that's not a good measure.) It seems like every car in my neighborhood has some kind of alarm. They go off a lot. I mostly notice it when I'm in my apartment, or on the bus, or walking somewhere...it's a painful addition to the general noise pollution.

Today, I happened to be near the car whose alarm was going off. I noticed which car it was (usually I don't, it's just noise to me). There were lots of people around, between the market and the takeout places and the dry cleaners. The prevailing reactions were "oh no, not again!" and "won't somebody shut that damn thing off?" rather than "stop, thief!"