Hate that sweater you got for Christmas from your aunt? You're not the only one. Retailers are bracing for the annual post-Christmas surge of returns on Friday. And they are getting ready for the onslaught of fraud, too. Merchants expect about five percent of all holiday returns to be fraudulent - for an estimated loss of $3.8 billion, according to a recently released survey by the National Retail Federation (NRF). One of the biggest challenges continues to be "wardrobing" - the return of a used but non-defective item, such as clothing or electronics.