When you pull out a laser pointer and get your cat to chase the dot of light around your house*, you are using a patented method of cat exercise. The rights are owned by Kevin Amiss and Martin Abbott (both of Virginia), who patented it in the early 1990s. In the abstract, they describe this method of cat exercise as:
A method for inducing cats to exercise consists of directing a beam of invisible light produced by a hand-held laser apparatus onto the floor or wall or other opaque surface in the vicinity of the cat, then moving the laser so as to cause the bright pattern of light to move in an irregular way fascinating to cats, and to any other animal with a chase instinct.
In other words, they own the rights on doing this with ferrets, as well.
This might also be a good time to note an NPR story from this week, which documents IBM and Halliburton attempting to patent the process of patent trolling.
Method of exercising a cat: United States Patent 5443036
*Fact: This game becomes more fun if you have a rug. Just run the light up to the edge of the rug and then turn it off. The cat will become convinced that the little red light has gone under said rug and you will get to amuse yourself watching your cat try to lift the corner of something heavy without the use of opposable thumbs.
Thanks, Sam Ley!