Following the arrest of five people in Britain in connection with the "Operation Payback" cyber-attacks in support of WikiLeaks, the FBI announced mass raids across the United States in connection with the case.

"FBI agents today executed more than 40 search warrants throughout the United States as part of an ongoing investigation into recent coordinated cyber attacks against major companies and organizations," a bureau press release states.

Though the bureau did not say if any individuals were arrested during the raids, it did confirm a link between the US raids and the arrests in Britain. The bureau said suspects, if charged, could face up to 10 years in prison.

The police actions indicate that governments on both sides of the Atlantic are determined to prevent hacktivists from taking revenge against companies that ceased to do business with WikiLeaks following the release of US State Department cables late last year.

Five men have been arrested in the United Kingdom for their involvement in "recent and ongoing" attacks by an online "non-group" of hacktivists that calls itself "Anonymous."

Three teenagers aged 15, 16 and 19 along with two men, aged 20 and 26, were arrested by authorities Thursday morning in connection with offenses under the Computer Misuse Act, BBC News reported.

"These arrests, and comments by ACPO threatening 'more extreme tactics' to deal with hacktivists represent a worrying ratcheting up of confrontation," Loz Kaye, Leader of Pirate Party UK, said in a statement. "Many in the online community frankly feel under siege. It is time for engagement from mainstream politicians, or otherwise radicalization can only increase."

In a campaign known as "Operation Payback" those participating in "Anonymous" succeeded in taking down the online operations of PayPal, MasterCard Worldwide, Visa, Swiss bank PostFinance and others using a technique called "distributed denial of service" (DDoS) attacks. The companies were targeted after they dropped their financial services to WikiLeaks.

DDoS attacks flood websites with meaningless web traffic to slow them down and can knock websites offline entirely.

Using Twitter and Facebook, "Operation Payback" invited thousands of people to voluntarily install a tool called LOIC (Low Orbit Ion Cannon), which was used to perform DDoS attacks on selected websites.

"As traditional means of protest (peaceful demonstrations, sit-ins, the blocking of a crossroads or the picketing of a factory fence) have slowly turned into nothing but an empty, ritualised gesture of discontent over the course of the last century, people have been anxiously searching for new ways to pressure politicians and give voice to public demands in a manner that might actually be able to change things for the better," the group said in a statement (.pdf).

"Anonymous has, for now, found this new way of voicing civil protest in the form of the DDoS, or Distributed Denial of Service, attack."

"Anonymous" noted that, unlike hacking, DDoS attacks do not involve "unauthorized access to a computer or network." Evgeny Morozov, a visiting scholar at Stanford University, compared DDoS attacks to a digital sit-in. "Both aim at briefly disrupting a service or an institution in order to make a point," he said. "As long as we don't criminalize all sit-ins, I don't think we should aim at criminalizing all DDoS."

"It is clear then, that arresting somebody for taking part in a DDoS attack is exactly like arresting somebody for attending a peaceful demonstration in their hometown," the statement continued. "Furthermore, the maximum sentence these 5 anons could be given under the Computer Misuse Act is 10 years imprisonment and a fine of up to £5000. We want you to realize just how ridiculous these sentences are, especially given the exact nature of a DDoS attack."

In early December, a Dutch teenager was arrested for participating in the cyber attacks. Unconfirmed sources said that the 16-year-old boy operated an "Operation Payback" chat room and was known under the nickname "Jeroenz0r."

Researchers in the Netherlands, at the University of Twente, found that using the LOIC exposed users to being identified unless traffic was routed through anonymous relay software, like Tor.

'Anonymous' takes aim at government websites

Late December, the Zimbabwe African National Union (Zanu-PF) website, Zimbabwean government website and Zimbabwean Finance Ministry website, were all targeted by "Anonymous" after Zimbabwean President Robert Mugabe's wife, Grace Mugabe, sued a newspaper for publishing a WikiLeaks cable that alleged she was connected with illicit diamond trade.

After successfully attacking the websites of the Zimbabwean government, "Anonymous" defaced the website of the Tunisian government with an open letter critical of the nation's censorship of the web.

"Remember, remember, that the tighter you squeeze the more your citizens shall rebel against your rule," the open letter stated. "Like a fistful of sand in the palm of your grip, the more you squeeze your citizens the more that they will flow right out of your hand."

Massive pro-democracy protests in Tunisia eventually forced Tunisian President Zine El Abidine Ben Ali to flee to Saudia Arabia.

On Wednesday, "Anonymous" expressed their support for protesters in Egypt by calling for cyber attacks on websites run by the Egyptian government.

Tens of thousands of demonstrators took to the streets across Egypt this week, facing down a massive police presence to demand the ouster of President Hosni Mubarak in protests inspired by Tunisia's popular uprising.

After reports said that social media websites Twitter and Facebook had been restricted in the country, the "Anonymous" Facebook page "Operation Egypt" issued a dire warning to the Egyptian government.

"To the Egyptian Govt : Anonymous challenges all those who are involved in censorship," the group wrote. "Anonymous wants you to offer free access to uncensored media in your entire country. When you ignore this message, not only will we attack your govt websites, we will also make sure that the international media see the horrid reality you impose on your people!"