https://www.youtube.com/watch?v=iVrJUbeuG44
Just saw this on the Youtube front page. Don't have anything negative to say about the dude really. I saw his older videos, he uses eye protection and shows off his laser projects inside his garage, so I don't see an issue.
But this build just seems pointless to me. The 5W blue diodes which he probably bought from DTR are arranged next to each other without knife edging so they are too far apart. Also there are no correction optics so the vertical divergence is pretty bad. A tight 40W beam could do more than pop balloons and burn paper at that rate which even <1W can.