WASHINGTON-The U.S. Secret Service Financial Crimes Division, a division of the Treasury Department, issued a memo to the Office of the Comptroller of the Currency to be distributed to all member institutions on fraud prevention with the issuance of the tax rebate checks. The memo warns financial institutions that cash U.S. Treasury checks they should give extra scrutiny to checks in amounts larger than $600, which is the typical maximum amount. The institution should double check the document and verify the person's identity. "All check cashing entities are encouraged to exercise increased vigilance and should review the U.S. Treasury's criteria and their own respective check cashing policy regarding proper acceptance/cashing of U.S. Treasury obligations and instruments," the memo read.