Method, system, and computer program products for identifying potentially fraudulent receivers of digital content. A receiver authenticates to an auditing service with data that should be unique to the receiver. The auditing service detects when multiple receivers attempt to authenticate with the same data, suggesting that a receiver has been cloned or duplicated. The audit service also detects when a receiver authenticates improperly, suggesting an unsuccessful and unauthorized attempt to duplicate an authorized receiver. Individual receivers may be networked together. To help protect a receiver's authentication data from tampering, at least a portion of the data may be digitally signed with a private key. The audit service may then verify the digital signature with a corresponding public key. Varying the order in which data is signed or where the data is stored from one receiver or group of receivers to another may provide an additional level of security.