There's a new email BOGO phishing scam that will advise that recipient that a purchase has been made for $500, and it must be confirmed. The idea is to get a user to call in and give the credit card number. They will then say they've reversed the charge, but in reality, you've given them your credit card number and three-digit code. Then they can charge on it.
Another scam, called the Vinnie Troya Scam, will claim to be from the FBI or DHS that has detected unauthorized activity by a Vinnie Troya and need your number to confirm and reverse it. Troya wrote a book about cyber security, so it's an attempt to discredit him.
Leo calls them "Bogo filter" scams, meaning that they are designed to trigger your bogus filter and get you to respond.
Check these email scams out at Krebs on Security Twitter feed here.