There was a service a while back called "Please Return Me" or somesuch. I found their Facebook page but it looks like it's dead. Anyhow they had tamper-resistan

There was a service a while back called "Please Return Me" or somesuch. I found their Facebook page but it looks like it's dead. Anyhow they had tamper-resistant labels with a serial number that you could put on devices. That way if it was lost, someone could get a reward from you to return it. A similar process might work with this idea. My one concern is that what happens if you have A selling legitimately to B, then B tries to resell to C? A could trigger the alert, making C think B is a thief.