Hotrod,
Sorry to hear about your loss. Unfortunately, it takes losing some items to thieves to remind us all that thieves lurk everywhere. It's best to keep personal items out of view and locked, whether you're at a park or shopping for groceries. There are no guarantees, of course, but it helps remove the temptation -- there's usually another "target" nearby that a lazy thief will hit instead.
There was a popular birdwatching park along the coast we used to frequent until it got a reputation as a hotbed for thieves. They'd break into parked cars and steal camera equipment, binoculars and other expensive items. The problem was addressed with increased patrols by the local police department, but the park lost its original reputation as a great place to go birding. In fact, we found the park overgrown and unattractive for birding on a visit earlier this year. I can't blame it entirely on the thieves and the fear they put on everyone, but it certainly didn't help.
I personally doubt that removing limbs would stop thieves; it would probably just force them into other methods, just as it does in those societies alluded to. I don't think we really want to emulate that kind of "justice" system. We can be barbaric enough, as a society, ourselves... without emulating barbarism from other societies.