Good kitty.
Years ago, I read a story about a woman who confronted a would-be rapist in her home. Her cat attacked the intruder, scratching him severely and leaving one of its claws embedded in the guy's cheek. He escaped, but he was so badly injured, he went to the emergency room, and that's where police arrested him.
We think of dogs as protectors, not cats, but some cats do have that measure of loyalty. Or maybe there is a selfish motive -- like maybe the cat thinks the intruder will harm it and who cares about the human it lives with. Allegedly, cats don't think too deeply, but who knows?