The raids come amid a recent spike in activity by Anonymous. Just last week, members of the group claimed credit for breaking into computers belonging to military contractor Booz Allen Hamilton and exposing the email addresses and passwords of more than 90,000 military personnel.

Earlier this month, Anonymous was labeled a cyberterrorism group by the Arizona Department of Public Safety after members of the group repeatedly attacked Arizona police union websites to protest the state's tough immigration laws. ln December, Anonymous launched a series of DDoS attacks against several organizations, including PayPal and Amazon.com, to protest what it claimed were efforts to stifle whistleblower site WikiLeaks.

Today's FBI raids shouldn't come as a surprise, said Josh Shaul, CTO of Application Inc. "They got a lot of people angry," he said. "When you play with fire you are going to get burned."

What is unusual, however, is that some Anonymous members appeared to have put little effort into concealing their tracks, he said. "It seems like these folks who got caught were brazen and careless about the way they went about their hacking activity."

Many of the recent attacks by Anonymous and splinter group LulzSec appear to be focused on embarrassing the victims, not about outright data theft or sabotage. Even so, "they [law enforcement officials] are certainly going to want to make an example of anyone they can bring in," Shaul said.