@Jon, by way of Herby

>> Have the "central control" send a message to self destruct.

>

>Because that would be hacking, which is illegal.

No, hacking is not illegal. In fact, I make a pretty good living hacking, and have done since roughly 1974. I'm in the open, I'm not hiding, you can find me in the 'phone book. Occasionally, even law enforcement and the court system asks me to help out with ... uh ... "stuff".

The problem with the "central control" concept is that there isn't such an animal. It doesn't exist, at least not within the current iteration of what we call "the internet".