Earlier this month there was a breach at Global Payments. They handle most major credit card companies such as Visa and Master Card. The origional breach was twards the end of March totaling in over 1.5 million compromised accounts.
WSJ has reported that there are up to 7 millions compromised accounts. Global Payments states that no names, addresses or social security numbers have been stolen, but that is unknown. Some people are estimating the amount of compromised accounts to reach over 50 million. Check you online statements and report any false charges to your credit card company immediately.