Yet there are many societies who would prey upon others and see it as justified. So it's still an arbitrary definition.

I would generally say that the answer to your question will depend on who you ask. If an individual has been victimised by a being so compelled they're unlikely to consider the fact it may be unable to not act in a given manner. Whereas someone who hasn't been in that position may be more sympathetic. But that doesn't really advance our discussion any. To really answer it we should ask if a creature is capable of overcoming the directives of its nature. If it is, then it surely can be held accountable for its actions. If it can't then it's as guiltless as any natural disaster.

You not asking because you're curious how many here might classify you or someone you know as a monster? [In general it seems most people only start asking such questions when they have a personal investment in the answer. But he's quick to wave the issue aside with a chuckle.] Forgive me, that was rude. I meant nothing by it and certainly enjoy the chance for such discussions myself.