The Legislature is considering a requirement to force all new cellphones to have a kill switch. If the phone is stolen, you can remotely command it to turn into a useless slab. This is intended to combat phone theft.
One problem: To discourage theft, thieves must know about the kill switch. They must think, "It is unwise to appropriate that person's property. It's not the moral issue or the inconvenience I will cause, no, it's that the purloined object will have no value. Best I return to my old trade of striking them on the head and taking their money, which can be exchanged for goods and services."
Is a law needed? You can already use the Find My Phone app to locate your iPhone, so the cops can knock on the miscreant's door. What? A phone? This? Some guy dropped it off. John — I don't know his last name. He just threw it through the window. I don't know, maybe he's like the Johnny Appleseed of phones.
The only way this will have an immediate effect is to let the phrase "kill switch" get out there without explanation, so the criminal thinks that the phone could literally be lethal. Put out some ads with a funeral director: Have you lost a loved one to the kill switch? We can help you through this difficult time. Run some fake TV spots that advise people what to do if they accidentally activate the kill switch: You will have 30 seconds to find a manhole, a river, a lake or a dumpster.
If thieves already knew from their own experience that failure to enter the proper security code would summon a Taser drone within 20 seconds, they would be unlikely to steal someone else's. But that's impractical. So:
Require a camera app that the victim can enable after a theft. It digitally adds blue ink to the face, so when the thief takes a selfie he thinks a dye pack exploded. Half of them would be dumb enough to turn themselves in.