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.
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.
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!"