Can't remove "Unknown User" from Remote Login

Hi,

Apologies if this has already been covered in another thread. I was unable to find my answer.

I'm able to erase regular accounts (I tried), but I am unable to delete the two accounts entitled "Unknown User."

I'm extremely comfortable at the unix prompt and don't mind getting my hands dirty by editing whatever I've gotta edit.

Any help is appreciated.

I'm running the latest version of Mountain Lion (10.8.2).

-Adam