Notorious hacktivist group Anonymous cost global e-commerce firm PayPal 3.5 million pounds after a student attacked its website as part of a concerted effort by the cyber hackers.
Christopher Weatherhead, 22, was studying at Northampton University when he allegedly took part in the campaign.
During Weatherhead's trial, the court heard that Anonymous targeted companies who opposed internet piracy but later attacked PayPal after it refused to process WikiLeaks payments.
But Weatherhead, from Northampton, denies a charge of conspiracy, and has pleaded 'not guilty' to conspiring to impair the operation of computers between 1 August 2010 and 22 January 2011, the BBC reports.
According to the report, MasterCard, Visa, Ministry of Sound, the British Recorded Music Industry and the International Federation of the Phonographic Industry were also hit by the attack.
Weatherhead, who used the online name Nerdo, posted plans on an Internet Relay Chat (IRC) channel encouraging an attack on PayPal, the court was told.
More than 100 workers from PayPal's parent company, eBay, spent three weeks to fix the issues related to the attacks, the report said.
The trial is set to continue. (ANI)