I don't think that you should have to be 18 to own a laser, but I do think that there should be some sort of license required in order to own a Class 3B or Class 4 laser. I'm 16, and I know a lot of people that would point a laser at their eyes and their friends eyes, even if they know the risks. For example, I told one of my friends about a 2W IR laser I am building as well as the risks that go along with it (I told him that it would be more than 2000 times stronger than a Dollar Tree pointer), and he responded with an, "Oh, that would blind you instantly, wouldn't it? Oh, you know what I'm going to do? I'm going to point it at my arm!" and then started laughing. He's normally quite responsible, but apparently I overestimated his capability of understanding plain-and-simple danger. I know that if he were required to read a handbook and take a knowledge then he would be a little more responsible, but I'm not sure that would be enough for everybody. I think the license would need to require something like an Oregon Driver's License would: not only a knowledge test, but also a demonstrative test showing you can physically handle a laser in a safe, efficient manner. That's just me though, I know many of you will disagree.