First off, the green laser pointers are no more powerful than the red ones- its just that they are at a wavelength that the human eye is much more sensitive to. SO the potential for damage to the eye is the same for both laser pointers.

Typical off the shelf cheap laser pointers are <5mW. They are NOT classified as eye safe by ANSI standards. It is my understanding that it takes farly long duration exposure to cause damage (There was a rather grotesque experiment done on a volunteer that was about to have his eye removed due to a tumor I believe)... It is more than just rude to flash someone with a pointer- it can have unforseen effects--

Visible laser pointers operating with 1-5 mW power are Class 3a and can be hazardous if viewed even for a very short time. Users should never look directly into the beam of Class 3a laser pointers, which are required by Food and Drug Administration (FDA) regulations to be marked "DANGER." (Class 2 lasers are labeled "CAUTION.") Possible hazards include startle effects, flash-blindness, glare, and after-images if a person is struck directly in the eye. Numerous cases of such incidents have been reported, along with cases where individuals overreacted to being flashed. Reports of those exposed include a pilot, bus drivers, sports figures, a teacher, and police (e.g., see the Rockwell Laser Industries articles.

In 1997 the FDA issued a warning on misuse of laser pointers (see Consumer Information on CDRH Topics). In some states such as California, it is a criminal misdemeanor to shine a laser pointer at individuals who perceive they are at risk, and it is a felony to aim one at an aircraft. Some local governments have passed regulations requiring anyone purchasing a laser pointer to be 18 years of age or older. It is expected that the pending revision of ANSI Z136.1 will have a special section commenting on laser pointers.

So, as you can see, while they are legal to purchase misusing them can really cost you. If you hit a plane with one and are caught it could send you to jail... saying "Honest, it was an accident..." may be hard to prove... on the other hand catching you will be tough unless you are doing it over and over- This IS a crime that is taken very seriously, and if you are INTENTIONALLY targeting planes then you DESERVE to have the book thrown at you. If you DO hit a pilot with a cheap laser pointer then you are not going to cause eye damage.... you may (in increasing order of severity) 1) just distract the pilot 2) disorient the pilot 3) temporarily ruin his night vision 4) temporarily blind the pilot- all these could lead to disaster and many deaths. The people that think this is a cute little gag should be shot.

The most publicized incident of this occurring was with something a lot more dangerous- An idiot with (I believe) a 250 mW green (Eye damage is a definite possibility with such a laser, even in very short duration exposure) laser in new jersey. He was intentionally targeting planes on approach or takeoff with his powerful green laser. He did it repeatedly from his house. The general neigborhood was identified by the affected pilots and officials sent helicopters to try to pinpoint the culprit. THE MORON TARGETED THE HELICOPTERS. His house was identified and he was arrested. At first the slimeball tried to blame his teenaged daughter, but finally he came clean. Last I heard he was being proscecuted for terrorist activities... I hope he gets the maximum.

Our 'laser pointer' is ~11-15 Watts, but this is spread over a circle .5 meters in diameter- so its intensity is actually less than that of a laser pointer. I have put my hand in the beam and not felt a thing, but it is NOT eye safe. We take great precautions to make sure there is no chance that we will distract a pilot. We have two airplane spotters outside at all times we are propagating watching for airplanes. If an airplane comes within 20 degrees of the beam the spotters will shutter the laser, additionally we have an infrared camera that can detect airplanes without running lights - if it detects anything near the beam it automatically shutters the beam. Prior to operating the laser we issue a Notice To Air-Men (NOTAM) with the FAA to advise them that we will be operating the laser. We test all of our interlocks every night prior to operations. Air traffic over the mountain is very rare- in all our laser nights we have only shuttered a few times for planes.

Hope this helps