Sony said it had detected a large number of unauthorised attempts to access user accounts on its PlayStation Network and other online entertainment services.
The Tokyo-based electronics giant said it had temporarily locked about 93,000 accounts whose IDs and passwords were successfully verified by the attempts.
Sony has sent email notifications and password reset procedures to those customers.
The company said credit card numbers linked to the compromised accounts are not at risk and that it has "taken steps to mitigate the activity".
The incidents follow an embarrassing data breach earlier this year, which compromised personal data from more than 100 million online gaming and entertainment accounts.
Sony confirmed the latest incidents after its security systems detected an unusually high number of log-in attempts that failed, said Sony spokesman Sean Yoneda.
The company suspects that those responsible obtained large data sets from other companies or sources, which were then used to try to access Sony accounts.
"What happened in April was a breach on our servers as we said in our announcements," Mr Yoneda said. "But this time around, there was no intrusion on our servers. This was ... taking someone else's identity and trying to use that to access our services."
The access attempts occurred between October 7 and October 10 and targeted accounts globally.
Sony's customer service centres around the world had not seen an increase in user calls related to the incidents, Mr Yoneda said.