What IS an evil robot?

SuicideBots-blog made me aware of a Richard Vaughan's initiative "No Evil Robots" - which basically sounds like a good thing, as the point seems to be to stand up against military-funded development of autonomous killer-appliances ...
But somehow, I think the slogan "Prevent evil robots from taking over the world:
Just say no to robot weapons and violent robot competitions." goes a little bit too far.
I know, as founder of a Cocktailrobotics festival I should feel encouraged - I myself don't want to encourage anybody to build robots that harm you more than giving you a headache from too many good drinks ... but a) I do enjoy watching battling robots once in a while myself and b) like with videogames I tend to belong to the faction that believes it might after all be better to channel destructive energies into some game rather than into human-to-human conflict.

So my own plea to potential killer-robot-builders is the following: Please, turn to building robots that fight robots - not humans, or any other organic slimeware.

Update: In an articulate statement pro violent robot competitions SB points out:
"I have a niggling feeling that DARPA is probably not going to use those Grand Challenge Prizewinning Technologies for helping Gramma cross the street.
Likewise, it might be true that Singapore is planning on using their civilian-engineer-developed robot army to distribute carnations down the imaginary invasions forces’ rifle barrels, but I doubt it.
Combat robotics is like boxing, only with all of the action and none of the blood. It’s all the really good bits of NASCAR strung together in eight minute intervals.
It’s eight-year-old girls begging their dads for Lego Mindstorms and Boe-Bot kits."
Couldn't agree more - I'm ready to see boxing replaced by robot fighting matches at any time.