You could have found out reading the thread from theymos about the recent hack.
The real question is why?
Yes, the trigger for my question was the statement of Theymos about that evtl. the account registration IP would have been stolen. And I was wondering, why that year old IP address would have to be kept in the database, while I think in the meantime I have proven not to be an attacker / spammer / bot, whatever bad.