Ok so you ebayed an account or whatever and your unsure of the original owners name as its masked.
How i found out was by basically abusing someone at elemental plateau for stealing my mob

he reported me and within a day or two i got an email from blizzard warning me that vulgar and obscene comments are not premitted:yuck:
The email has the owners FULL NAME at the top of the email.
Unlike botting etc its unlikely to get u banned, and better than just randomly giving ppl stick just get a friend to speak to a gm to report you.
For those who may wonder what i said to the guy, it involved his mother, a gorilla and a tube of ky jelly
Hope this helps somewhat