I think we've all seen Robocop and know how this works out. I am all for technology making our lives better, but autonomous robots (or even remotely controlled ones) that go around killing people at will isn't the future we should have. Theoretically it's a good idea, until for one reason or another you end up on the kill list. And then it doesn't matter who hacked it or how you go there, you're no longer available to argue. Seems like an awful idea.