Hmm, I live in Minnesota and haven't heard of the owls here taking full- grown cats before - I'd expect one to be able to lift one off the ground perhaps, but not get far before it had to land again. Eagles and hawks are another matter; if they're hungry enough they'll take a cat or small dog - a bald eagle is pretty huge (and quite common around here). I wonder if there's a bit of a mix-up of stories going on...
cheers
Jules