HSBC recently confirmed that it had suffered a cyber attack that took down several of the bank's websites around the world.
The company was hit by a denial of service attack, which limited access to its websites and online banking services. The attack, however, "did not affect any customer data," HSBC said.
"We are taking appropriate action, working hard to restore service. We are pleased to say that some sites are now back up and running," the bank said. "We are cooperating with the relevant authorities and will cooperate with other organisations that have been similarly affected by such criminal acts."
The @FawkesSecurity Twitter account said it took down hsbc.co.uk, tweeting at the bank: "We just brought down your site." The group later attacked hsbc.ca and hsbc.fr.
The group also suggested that other banks, like Barclays, might be next on the attack list.
Why attack HSBC? FawkesSecurity, which said they are not a UK-based group, argued that "British banking systems are corrupt and only profit those in high places."
Many customers were annoyed that they were unable to access their accounts and tweeted at FawkesSecurity, but they just responded by mocking and re-tweeting the angry tweets.
The hack, meanwhile, comes amidst what is known as Operation Ababil, or attacks on US banks over the fact that the controversial film Innocence of Muslims is available online in the States. As Betabeat noted, the campaign recently entered its fourth week by targeting Regions Bank, but has also affected Capital One and SunTrust.