I totally agree that you must be responsible with the use of any laser.
I own two of them, One of them is probably illegal, it far exceeds the 5 milliwatt limit.
I won't say were I purchased it, but it can light a match! that one stays locked up with my Guns. I consider them a dangerous weapon, even a 5 milliwatt laser can cause permanent damage to anyone's vision
As an educational tool they make pointing out the constellations to newcomers so much easier, but I take extra care that no aircraft are in the vicinity when I use it.
I can also use it to temporarily shut off street lamps with it. it only lasts about 5 minutes and then I have to hit the sensor again .
It helps when I can't get away from my driveway since I have a street lamp right in front of my house only 25 ft away. I just keep hitting the sensor every couple of minutes while I am taking images.