A method and apparatus for protecting privacy in power line communication (PLC) networks. Data transmitted on a PLC network is encrypted according to a network key and can be properly received only by registered devices that have the proper network ID and network key value so that proper decryption can be performed. According to the invention a streaming media device is provided with a compatible network ID and network key during a registration process facilitated by coupling the device (applicant) to a direct power line connection associated with another device (administrator). The network key, and optionally network ID, are then shared over the direct connection without being distributed over the PLC network at large. By way of example, the data is prevented from being distributed across the PLC network in response to using selectable filtering of PLC data, and preferably a secure data communication mechanism, such as public-private key encoding.