Today the hacker group Anonymous announced on their Twitter profile that they had successfully hacked MasterCard’s website.
There is probably talk about a DDoS attack which basically puts the servers to their limits and makes them crash because of too much load.
It is about half a year ago that Anonymous got formed, and since then they have been behind a series of attacks on payment instututions because they cut off Wikileaks.
As a side note regarding the posts I have wrote about Lulz Security, it seems that from some sources that Anonymous and LulzSec have merged together after that LulzSec said that they would disband.