Moreover, that other proces need not be on the same server, or even on a server that you control; worse, it could trigger a meatspace effect. "User now authoriz

Moreover, that other proces need not be on the same server, or even on a server that you control; worse, it could trigger a meatspace effect. "User now authorized, access granted, door opened. [five minutes pass] Oops, that was a mistake." How do you undo _that_?