British newspaper The Times had done a research on the sale of illegal creditcard information of British citizens.
According to The Times between 300 and 400 creditcard numbers are sold each night of British citizens. It is mostly gangs from Eastern Europe and South East Asia who are involved in this type of criminality.
The gangs use IRC channels to sell the information. A creditcard number is worth 1$ and a creditcard number together with the security number is worth between 3$ and 5$.
The creditcard information is usually obtained by compromising websites where customers have used their creditcards to pay.