A leading player in the distributed denial-of-service (DDoS) attacks in the name of activist hacking collective...
Anonymous, in 2010 and 2011, has been convicted.
Christopher Weatherhead, 22, who had entered a plea of "not guilty", was convicted on one count of conspiracy to impair the operation of computers, contrary to the Criminal Law Act 1977.
A jury returned a guilty verdict against Weatherhead for his "integral role" in the attacks, which happened while he was studying at Northampton University, according to the Guardian.
He worked with Peter Gibson, 24, of Hartlepool, Ashley Rhodes, 28, of south London, and Jake Birchall, 18, of Chester who all previously pleaded guilty to the same charges.
MasterCard, Visa, the British Recorded Music Industry (BPI), the Ministry of Sound and the International Federation of the Phonographic Industry were also hit.
The cyber attacks were made using a free tool downloaded from the internet called Low Orbit Ion Canon (LOIC).
Read more about DDoS attacks
Anonymous's Operation Payback originally targeted companies involved in the music industry and opponents of internet piracy, but was later broadened to include revenge for WikiLeaks after the backlash against the site for publishing thousands of US diplomatic cables.
Judge Peter Testar warned Weatherhead he could face jail when sentenced at a later date with his three co-accused.
"I want to have as much information as possible before deciding what should happen in the case of these four men," he said.
The trial heard that Weatherhead spent up to 10 hours a day online and dreamed of working for Amazon or Google.
He refused to admit that he had been part of the attacks, claiming to have been the communications manager for Anonymous and the creator of online chatrooms where the attacks were planned.
Weatherhead was released on bail until sentencing in January. But the judge ordered that he be tagged electronically and subject to a curfew.