Alleging he was a victim of identity theft, William R. Rosa accused a law firm of violating the Fair Debt Collection Practices Act when it tried to collect on $9,427 in credit card purchases he attributed to a crook. But because the FDCPA only applies to consumer transactions, Rosa had to establish that the thief’s purchases weren’t “commercial.” Courts are split on what evidence victims of identity theft have to present to establish that debts they didn’t incur qualify for protection under the FDCPA.Rosa relied on the …