US videogame giant Electronic Arts (EA) has revealed that hackers had looted user data in "a highly sophisticated" attack.
A computer network hosting BioWare Edmonton's Neverwinter Nights game forums was hit by hackers who made off with users' names, passwords, email addresses, birth dates and other personal information, EA said at its website.
"The server system associated with the Neverwinter Nights forums was the target of a highly sophisticated and unlawful cyber attack," EA said.
"We have moved swiftly to implement additional security controls to prevent this type of breach from happening again to secure your data and are conducting further evaluations now," the message continued.
No credit card information was taken in the hack, according to the Northern California-based firm.
EA was the latest in an unrelenting string of cyber attacks with targets ranging from Arizona police and the Central Intelligence Agency to videogame makers and the US Public Broadcasting Service.
Sega on Sunday released word that hackers had stolen the personal data of some 1.29 million customers of the Japanese game maker in a theft via a website of its European unit.
The Sega Pass website, operated by London-based Sega Europe, did not contain credit card information, the Japanese firm said.
But names, dates of birth, email addresses and encrypted passwords were stolen by intruders to the site, Sega said in a Japanese-language statement.
A series of hacker attacks on Japanese electronics and entertainment giant Sony in April forced it suspend online services for weeks.
Sony suffered one of the biggest data breaches since the advent of the Internet, with personal data from 100 million accounts compromised.