Four Anonymous hackers recently took down the websites of PayPal and Ministry of Sound with a huge volume of messages and requests, otherwise known as a DDoS attack. The entire act was carried out under the name Operation Payback, and caused losses worth more than £3.5m in revenge for the backlash against WikiLeaks and the founder Julian Assange.

Those who visited the said websites were shown the message, “You’ve tried to bite the Anonymous hand. You angered the hive and now you are being stung.” Besides, the hacktivists forced the MasterCard and the recording industry to go offline.

One member of Anonymous involved in the attack is currently in court in the UK up on charges related to the attack and the loss of money that occurred. The accused, Christopher Weatherhead, 22, a student at Northampton University, is known to have gone by the online handle of “Nerdo” and stands accused of being part of a small leadership who coordinated the attack.

“Christopher Weatherhead, the defendant, is a cyber-attacker, and … he and others like him waged a sophisticated and orchestrated campaign of online attacks that paralysed a series of targeted computer systems belonging to companies, to which they took issue with for whatever reason, that caused unprecedented harm,” said Sandip Patel, the prosecutor.

“The members of Anonymous describe themselves as hacktivists … They conducted online attacks against computer systems which they took the view, for whatever reason, needed to be dealt with, taught a lesson. Their method was to carry out DDoS attacks in order to bring them down,” Patel added.

The hacker group used a free internet tool called Low Orbit Ion Canon (LOIC) as a destructive cyber weapon. It works in the way when the volume of traffic sent to a computer becomes too much for it to handle it would suffer a denial of service. The more LOICs used, therefore, to attack a target computer, the more likely that a denial of service will take place.

Not only PayPal, the hackers also attacked the British Phonographic Industry on 19-20 September 2010, though the DDoS did not shut the site down. Four websites operated by Ministry of Sound were also attacked between 3 and 6 October. This resulted in the forcing of International Federation of the Phonographic Industry to spend £20,000 as a result of being attacked between 27 November and 6 December.