A group called the Yorkshire Posse apparently hacked into several corporate Web sites last Sunday evening.
The group said 13 companies were targeted to protest the arrest last April of Canadian Jason Mewhiney, who is suspected of breaking into a NASA Web site and causing tens of thousands of dollars in damage.
"I think they went for us because we were a high-profile site," said Sara Winge, a spokeswoman for information technology publisher O'Reilly & Associates in Sebastopol, California, one of the sites that was hit. "They were trying to get a message across about a Canadian hacker -- or cracker, I guess I should say -- who was being tried for computer crimes. But it didn't have anything to do with O'Reilly as a company."
The hacked sites were replaced with a page that proclaimed a "declaration of war against all who would challenge the freedom of Canadians with such ludicrous actions!"
The group claimed to have also hit Playboy.com, Sonymusic.com and a Sun Microsystems customer support site in Canada. Officials from those companies weren't available for comment at press time.
Winge said O'Reilly was contacting the other 12 sites to learn how the group carried out the attacks. "We obviously can't give a lot of detail, but we have prevented it from reoccurring at this point," she said.
"All of our electronic-commerce offerings are on another server, which was not at all touched and has much heavier security," Winge added.
She said the attack occurred late Sunday night and was fixed by 9am Monday morning.