The Metropolitan Police are to investigate the distributed denial of service (DDoS) attack carried out by Internet gathering Anonymous against Master Card, PayPal and Visa.
The "online living consciousness", which targeted several major recording companies under Operation Payback, has recently turned its efforts towards helping WikiLeaks, attacking the websites of several companies that allegedly severed ties with WikiLeaks after being pressurised by the US government.
The DDoS attacks, which involve bringing a website down by sending a barrage of user requests, are deemed illegal in the UK.
Scotland Yard told The Guardian that it had been investigating a number of cyber crime acts committed by Anonymous over the past few months.
“The Metropolitan police service is monitoring the situation relating to recent and ongoing denial of service attacks, and will investigate where appropriate,” the Met said in a statement.
Anonymous is currently planning to unleash Operation Paperstorm, encouraging members to go out into the streets and 'spam' the streets with posters and flyers.