My comment to an entry 'How'd you end up with your handle?' by cigarskunk2
Back in the BBS days (Mitch should remember them) I used "Deep Thought" on the Philadelphia area scene. Later, when I got my first Internet account (1991, my sister's unused student account at the University of Maryland) I needed 8 letters or less. I was torn between RussPost (from Those Annoying Post Brothers) or, my love for the Broomhandle Mauser, and Mauser it was. And for the longest time, I never ran into another Mauser on Usenet.
Eventually I did run into sites where it was taken, so I started using Mauser712 (DeviantArt is one of the few still using that) and after starting to write about a Mad Scientist, I started using Dr. Mauser (or Dr_Mauser) as necessary.