I filed several of these recently and I put zero in the dollar amount. I was probably wrong, but like you, didn't really know what I should put. The customer's activity wasn't suspicious - they just provided a false ssn to us when the account was opened. In a couple of the situations, the accounts had been opened since the 1990's and the ssn wasn't used for anything other than we requested one at account opening and that's what they gave us.