A group of hackers says it is planning another wave of cyberattacks against Sony in retaliation for its handling of the PlayStation Network breach.

An observer of the Internet Relay Chat channel used by the hackers told CNET today that a third major attack is planned this weekend against Sony's Web site. The people involved plan to publicize all or some of the information they are able to copy from Sony's servers, which could include customer names, credit card numbers, and addresses, according to the source. The hackers claim they currently have access to some of Sony's servers.

Should the planned attack succeed, it would be the latest blow in a series of devastating security breaches of Sony's servers over the past month. The failure of Sony's server security has ignited investigations by the FBI, the Department of Justice, Congress, and the New York State Attorney General, a well as data security and privacy authorities in the U.K., Canada, and Taiwan.

Several weeks ago the hacker group known as Anonymous targeted several Sony Web sites, including Sony.com and SonyStyle.com, with a distributed denial-of-service (DDoS) attack in retaliation for what its members saw as Sony's unfair legal action against hacker George Hotz. Two weeks ago Sony's PlayStation Network, along with its Qriocity service and Sony Online, were the target of an attack that exposed the personal information of more than 100 million Sony customers. Sony was forced to shut down PSN, Qriocity, and Sony Online, and is currently working to bring them back online after rebuilding the security of its servers.

Sony says it doesn't know who orchestrated what it's calling a "highly sophisticated, planned" attack, but it has dropped hints that the group Anonymous is involved. Kazuo Hirai, chairman of Sony Computer Entertainment, told a Congressional subcommittee in a letter yesterday that the intruders on its servers planted a file named "Anonymous" containing the statement "We are Legion," part of the group's tagline.

Anonymous issued a statement yesterday denying it was involved in the PSN breach. "While we are a distributed and decentralized group, our 'leadership' does not condone credit card theft," the statement said.

Now it seems the same group of hackers that was able to infiltrate the PSN servers is planning to hit back against Sony.

Sony did not immediately respond to a request for comment.