I was chatting frequently with a person with a 3 letter screen name back in 2001 - and then they just disappeared - I wonder if they are one of the lucky few who got jacked with this.
It's possible, however most people I knew in this scene mostly did longer usernames that represented the handle (mine included) that the person desired, mine was 7 characters in length that I requested. I don't remember many people asking for 3chars, however there was a lot of cracking, many of them had mind-blowing easy passwords that I did not even need a large password list to break into just a handcrafted one. I still have a list of 3 chars somewhere in my archive depot that I acquired, only 1 was contacted by the owner from a new account asking for their username back which I relinquished.