One problem, besides taking all of our eyes away from the altimeter and airspeed etc which is a bad idea, is the risk to our eyes if trying to just see where it comes from, another really bad idea. How could we begin to locate the origin? A suspect and conviction would help deter wannabes.
A police helicopter would really help. Maybe the spotter could wear goggles used during early nuclear tests and mark the laser origin with his own laser until the pilot circles the, eh, 'target', and helps the local squad car to find the jerk(s).
Taking any such jerk on a tour of the local prison, having lunch with potential pals, might result in 'behavior modification'.