Kevin, there are legitimate reasons for using a laser brighter than the typical 5mW output. None of them apply to someone lucky enough to have dark skies every night. Perhaps a park rule could be enforced for your situation. It's far removed from my astronomical world. I started with a 5mW laser, which was fairly visible from a dark site. From the suburbs, where most of the star parties I've ever been to have been held, 5mW is not bright enough. Only those fairly close to the beam axis can clearly see it. From a Harmons parking lot, for example, forget it on some nights. Yes, sometimes they are sufficiently visible, but not always. A lot of dust or water vapor in the air contributes to beam visibility. A 20mW laser is much better from the suburbs, but not for large groups. On some nights when the air is particularly transparent, such as after a frontal passage, even the 20mW laser visibilty suffers. The 100mW laser is easily visible to all star-party attendees from even heavily light-polluted, urban locations. Places where there aren't even enough visible 4th magnitude stars to verbally describe where the telescope is pointing. Attendees with poor vision, even those with "low" vision have been able to see the 100mw beam with ease. Astro-imagers are far more likely to have their images ruined by night-flying aircraft or satellites, than a laser pointer. Visual observers are typically not affected, based on my own, admittedly non-scientific visibility tests held at SPOC two years ago with a 20mW laser pointer. I believe the planetarium director owns a 100mW laser, purchased expressly for use at public star parties. A former SLAS president owns a 50mW laser, again purchased solely for it's excellent visiblity. Both have stated that 5mW lasers had very limited use as educational pointers. Neither of these people found themselves at truly dark sites for the majority of the star-parties they lectured or assisted at. A 5mW laser is just as capable of blinding the operator of a ground vehicle or aircraft if misused, as a higher output device. Perhaps pilots could be encouraged to wear laser safety glasses (less than $50 ea., typically) for landing, if they are concerned. I'm sorry, but the "keep the power down" stance does come off as sanctimonious to me, when applied this broadly. I certainly won't use one within the confines of Bryce Canyon, however, or any other sufficiently dark site. A reminder that in Utah <http://en.wikipedia.org/wiki/Utah> it is a class C misdemeanor <http://en.wikipedia.org/wiki/Misdemeanor> to point a laser pointer at a law enforcement officer<http://en.wikipedia.org/wiki/Law_enforcement_officer>and is an infraction <http://en.wikipedia.org/wiki/Infraction> to point a laser pointer at a moving vehicle.[33]<http://en.wikipedia.org/wiki/Laser_pointer#cite_note-32> Kim, the laser will dim when either the temperature gets too cold or the battery output drops below a certain level. It happens to mine, too.