Sony Corp., struggling to restore online entertainment services after a record theft of customer data, said Wednesday its PlayStation blog has been partially disrupted after the website was attacked by hackers.

Sony boosted the blog's security system following attacks on the site last month, Makiko Noda, a spokeswoman for the Tokyo-based company, said. The new system is likely the reason why some access by users outside the U.S. has been denied, she said.

The maker of PS3 game consoles was targeted in a "large-scale, coordinated denial-of-service attack" in April by the group called Anonymous in a protest against Sony for suing a hacker, Kazuo Hirai, the company's executive deputy president, said in a statement last week. The PlayStation blog was among the services attacked, Noda said.