[philwelch]

David Langford's Three Laws:

1. A robot will not harm authorized Government personnel but will terminate intruders with extreme prejudice.

2. A robot will obey the orders of authorized personnel except where such orders conflict with the Third Law.

3. A robot will guard its own existence with lethal antipersonnel weaponry, because a robot is bloody expensive.

(Langford is an SF writer. You might know him from his "basilisk" stories--if not, go read them sometime.)