It's cool. It's fun. It has an ever so slight edge of danger.... But it can give some fascinating results.
Yes, it is photographing broken lightbulbs.
(examples below found here: https://www.flickr.com/photos/amoringello/sets/72157642511037734/)
I've been wanting to do this for years. With all of the days off work due to snow this year, I finally got the time grab the necessary supplies gave it a whirl.
There is not all that much to it. A little preparation, a little safety, and a bit of luck to go along with it.