I saw a video once, I think on When Animals Go Bad or something that showed a cat go off on an animal control officer. It climbed up his leg and dug in. This was a big strong guy and he was screaming in agony, and he couldn't get it off without ripping his flesh even worse.
Cats are interesting animals. I seriously doubt I could take my cat without weapons. Funny how such a soft sweet little bundle of fur can turn into a ball of teeth and claws in the blink of an eye.
I kind of like that... it's more compatible with the human ethos than a rabbit, say, that can die of fear if a cat is in the general area.
I've had two cats exhibit behavior that (in a dog) would be considered protective.
Of course, one of them was a ferel cat and he was, at best, unpredictible. The only human he trusted was myself and it did not do for him to misinterpret your intentions. He wasn't exactly cuddly.
My current male tuxedo cat is very sweet and cuddly with the family, but he did considerable damage to a door to door salesman that was irritating me.