Credit card database hacked

security       2003-02-18 
A computer hacker has gained access to more than 5 million Visa and Mastercard credit card accounts in the US.
The two companies said on Tuesday that none of the information obtained, which would include credit card numbers, was used in a fraudulent way.
But a UK-based business crime expert warned account holders could still be at risk if their cards were not reissued.
Visa and Mastercard said the hacker breached the security system of a company that processes credit card transactions on behalf of merchants.