Several other sites including MasterCard, Visa, Ministry of Sound, the British Recorded Music Industry and the International Federation of the Phonographic Industry were also hit by attack
A British student studying at Northampton University in the UK, said to be a member of Hacktivism group Anonymous is on trial for allegedly hacking into e-commerce company eBay's PayPal, resulting in loss of trading worth £3.5m.
The student named, Christopher Weatherhead, allegedly took part in the campaign which also targetted some other websites including MasterCard, Visa, Ministry of Sound, the British Recorded Music Industry (BPI) and the International Federation of the Phonographic Industry (IFPI).
PayPal was attacked by launching Distributed denial of service (DDoS) to overwhelm the systems with flood of requests after the company refused to process the payments of Wikileaks.
Weatherhead however denied the charges of conspiring to attack the computers between August 1 2010 and January 22 last year, according to BBC.
Apart from Weatherhead, the jury at Southwark Crown Court in London were told Ashley Rhodes from Camberwell; Peter Gibson from Hartlepool; and an 18-year-old male who cannot be named for legal reasons have already pleaded guilty to the charge.
The hackers named the operation as 'Operation Payback', which had originally started as a campaign against the music industry and those involved in anti-piracy measures.
The campaign follows legal proceedings against the Pirate Bay website which had attempted to distribute music in breach of copyright laws.
Earlier this month, Anonymous had launched a series of cyber attacks against websites in Israel following its assault on Gaza.
In August this year, Anonymous had claimed it attacked and forced offline a number of the UK government's websites in response to its treatment of Julian Assange.