I'm pretty sure I received today my first "user removed," which resulted in a loss of ten reputation points, but I am at a loss to know what it means. Would someone please explain? Thanks. Don
It simply means that some user account was removed from the system and their votes went with them. This can happen when a user requests deletion or when a fraudulent duplicate account is detected.
It's nothing to worry about. Your reputation point loss wasn't even that much. I lost about 500 a while back on another site when an active high rep user decided to remove himself (and had apparently left me quite a few votes over time).