I disagree with those of you who are calling these guys idiots. Rather than condemn this kind of thing, we should encourage it. Experiments like this can be done safely if reasonable precautions are taken, and a lot can be learned as a result.
I don't know about you younger guys, but when I was a kid, we all had chemistry sets, experimented with home-made fireworks, high voltage electricity, and other things that today's parents would have a stroke if they knew their kids did that kind of thing. None of us died doing this stuff, but we certainly learned a lot that you just can't get by reading books and listening to stories from old-timers.
It was this kind of backyard experimentation that led many of us into technical careers that we wouldn't have considered otherwise. Our present society, which shuns perceived "danger" in any form, is stifling this sense of adventure and the result will be fewer people going into technical fields, and the ones that do will be mostly the 9-5 "it's just a job" type.
There was an interesting op-ed piece along these lines recently in QST (American ham radio magazine):
http://dissonance.nl/dz/kl7aj-oped.txt