According to John Ciribassi, DVM, DACVB, the problem with laser pointers is that they lack an endpoint. Nothing is ever physically caught. Even if the cat is “successful,” there's no reward. Such pointless play, says Dr. Ciribassi, can cause some cats to develop a compulsive disorder.
My cat once set up a magnetic field “vacuum bottle” of super cold sodium atoms, shined the laser through it, and successfully slowed down the particles of light to a mere 38mph!