A method for tracking media signals in multimedia content is provided by
uniquely identifying the multimedia content with a digital watermark
identifier. A video channel is preferably embedded with a first watermark
identifier. The first identifier uniquely identifies the multimedia
content or the content family. A second digital watermark is embedded in
an audio channel of the multimedia content. The second digital watermark
uniquely identifies a user or user device. When the multimedia content is
found in an unauthorized or unexpected channel, the content can be traced
back to its misappropriating source via the user identifier.