Something I really liked in GURPS Transhuman Space were the "Autonomous Kill Vehicles" (tiny robotic warships) which had been left scattered throughout the solar system by both sides in the wake of an interplanetary war. Although in theory all of these were supposed to have self-destructed, in reality the combatants were less than thorough about this and even when they tried . . . space is BIG. So every so often, one of these relics encounters an "enemy" ship and attempts to follow it's original programming . . . 

I think such things would make dandy additions to random space encounter tables, in any system which has seen combat involving Zhodani forces (given their passion for war droids). The existence of such a danger could also serve as justification for civilian vessels to carry light defensive armaments (assuming risk of pirate attack isn't a major concern in YTU).