Four men will be sentenced today for carrying out cyber attacks with hacking group Anonymous.
The so-called "hacktivists" took part in distributed denial of service, or DDoS, attacks - one of which cost the PayPal website £3.5 million.
The attacks paralysed computer systems by flooding them with an intolerable number of online requests.
Victims' websites would be directed to a page displaying the message: "You've tried to bite the Anonymous hand. You angered the hive and now you are being stung."
Northampton University student Christopher Weatherhead, 22, was convicted last month for taking part in the DDoS attacks, which also hit the sites of Visa, Mastercard, Ministry of Sound, the British Recorded Music Industry and the International Federation of the Phonographic Industry.
His trial at London's Southwark Crown Court heard that PayPal was attacked repeatedly between December 8 and 17, 2010 after it decided not to process payments on behalf of the Wau Holland Foundation, an organisation involved in raising funds for WikiLeaks.
Weatherhead, of Holly Road, Northampton, was found guilty of conspiring to impair the operation of computers between August 1, 2010 and January 22, 2011.
He will be sentenced at the same court today alongside Ashley Rhodes, 27, of Bolton Crescent, Camberwell, south London, Peter Gibson, 24, of Castletown Road, Hartlepool, and Jake Birchall, 18, from Chester, who all admitted the charge.