According to Dutch private investigation company Ultrascan, the highest-ever annual losses for advance-fee frauds (aka 419 scams) occurred in 2009. Computerworld reports that the company estimates victims lost at least $9.3 billion last year, compared with $6.3 billion in 2008.
The scams basically involve sending a fraudulent e-mail that tries to trick a victim into sending money with the bogus promise of some greater reward. Most people recognize such scams, but obviously some don't. Ultrascan calls them the world's most successful scams.
The top three countries for losses in 2009 were the United States, UK and China.