LONDON: Credit card giants MasterCard and Visa came under intense cyber attack on Wednesday as supporters of WikiLeaks retaliated for moves against Julian Assange after the release of US diplomatic cables that angered and embarrassed Washington.
The Swedish prosecution authority, whose arrest order for Assange over accusations of sexual offenses led a British court to remand the 39-year-old WikiLeaks website founder in custody, also said it had reported an online attack to police.
Assange’s online supporters hit the corporate website of credit card firm MasterCard in apparent retaliation for its blocking of donations to the WikiLeaks website.
“We are glad to tell you that http://www.mastercard.com/ is down and it’s confirmed!” said an entry on the Twitter feed of a group calling itself AnonOps, which says it fights against censorship and “copywrong.”
The same group claimed responsibility for bringing down Visa Inc’s site, which was temporarily unavailable in the United States, but later restored.
Visa spokesman Paul Cohen said its processing network “is functioning normally and cardholders can continue to use their cards as they routinely would. Account data is not at risk.”
Mark Stephens, Assange’s principal lawyer in London, denied the WikiLeaks founder had ordered the cyber strikes, which appeared to target companies seen as cooperating with efforts to rein in WikiLeaks.
Assange “did not give instructions to hack” the company websites, Stephens told Reuters.
MasterCard, calling the attack “a concentrated effort to flood our corporate website with traffic and slow access,” said all its services had been restored and that account data was not at risk.
But it said the attack, mounted by hackers using simple tools posted on the Web, had extended beyond its website to payment processing technology, leaving some customers unable to make online payments using MasterCard software.