This is a genuine question, please don't take this as sarcasm or something. But I have no "good reason" for buying this. I just want to have a very powerful laser I can use. Can you tell me "good reasons" for owning a laser like this? I'm curious because although I will be really careful and wear glasses, but in the end, I will be buying it "just for fun" and I don't see anything wrong with that.
Sure, see this:
Reflections from shiny surfaces alone can cause permanent vision damage. To the person earlier who said this is like looking into the sun, it's quite a bit more power than that. If the laser can ignite a match, what do you think it will do to the delicate cells in the retina of your eye?
Shine the laser on a white wall, damage someone else's eyes, what other reason do you need? Just for fun. It is not like there a reason for these things to be banned, they are just silly little toys (that can cause blindness) that shine in real pretty colors. So pretty. I'm pretty sure spending 200+ dollars to burn some masking tape and matches with the laser is going to be worth the risk. Specially with the super-high quality googles that surely will come with the laser.