A hacker going by the name of Reckz0r, claims to have targetted over 79 banking companies in a three month period, apparently gaining details to thousands of Visa and Mastercard customers. Overall, he boasts to have gained over 50GB of data from customers in the United States and further aboard, including the United Kingdom and Canada.
A section of the data has been posted up on the internet, with some details included such as customer names and card types, but the actual details of cards have been removed. A pastebin post by Reckz0r explains that such details were not included due to security reasons.
The hacker claims to have attempted to gain the data only because he was curious and wanted a challenge. If this is indeed confirmed, we are sure the majority of customers would prefer that curiousity be put to better use. Earlier this year, Neowin reported a story to which Visa and Mastercard confirmed that they may well have been victims of a "massive" data breach. Whether these two incidents are related, remains unclear.
It's important to remember this has yet to be confirmed by the banks in question and there are those on twitter that claim the details were gained through a phishing form on the internet, rather than through gaining unauthorised data. The fact that some of the data appears to be 'unnormalised' supports that claim.
Reckz0r or "Jeremy", has posted several tweets which talk about vulnerabilities in various software, including Norton Antivirus, cPanel and has even posted account details for an online porn website.