In Predators, you play as a predator. That needs to be stated up front, lest there be any confusion as to which side you're on. You're a murderous alien, and you tear the insides out of puny humans one after another. Normally such behavior would be a no-no, but it's permitted here for several reasons: 1) they're on your planet, 2) they're trying to kill you, and 3) back on Earth they're criminals who did very bad things. Really, they had it coming.