They're cool animals. I saw one while fishing a public lake about 12 years ago. It was around the same time a pair of them completely cleaned all fish out of my cousins 1 acre pond. They can be very destructive like this article describes.
I had a family that lived in the creek behind my home when I lived in So. Car. Cute as hell when they were playing around. But they were vicious when attacking and eating turtles and fish.