Board Thread:Game Discussion/@comment-99.242.96.196-20130525191154/@comment-13789016-20130807140156

u can make purchases with a spark or gamer account. My email that i was using to contact them with was the same as the billing email for my app purchases, so that was likely their identification check. However skimpy that is... obviously the account in question for me was inactive for several days because i couldn't access it (more evidence).

they do use device identifiers to identify who you are; but my case was that i had switched phones and my old phone was not with me any longer.