Credit card thieves have become increasingly bold and sophisticated in the black market of card numbers and other data like your CV2 information. The CV2 is a security code, usually the last 3 digits, that can be found on the reverse of most cards, usually on the signature line. Either way, the article I came across describes in detail about an online supermarket of stolen credit card information.

See link for the full article:

http://www.techworld.com/security/news/index.cfm?newsid=11808&pagtype=samechan