The latest breach follows a massive hack in April 2011 that led to the theft of names, addresses and possibly credit card data belonging to 77 million user accounts.
The latest hack, flagged by Sony as "a large amount of unauthorized sign-in attempts," led to the hijacking of valid sign-in IDs and passwords.
From Sony's statement:
Less than one tenth of one percent of our PSN, SEN and SOE consumers may have been affected. There were approximately 93,000 accounts (PSN/SEN: approximately 60,000 accounts; SOE: approximately 33,000) where the attempts succeeded in verifying those accounts’ valid sign-in IDs and passwords, and we have temporarily locked these accounts. As a preventative measure, we will be sending email notifications to these account holders and will be requiring secure password resets or informing consumers of password reset procedures.
The company said credit card numbers associated with these accounts are not at risk as a result of these unauthorized attempts.
"Only a small fraction of these 93,000 accounts showed additional activity prior to being locked. We are continuing to investigate the extent of unauthorized activity on any of these accounts," Sony added.