A dynamic multimedia fingerprinting system is provided. A user requests multimedia content from a Web cache server that verifies that the user is authorized to download the content. A custom fingerprint specific to the user is generated and dynamically inserted into the content as the content is delivered to the user. The custom fingerprint can be generated on the Web cache server or at the content provider's server. The system allows a content provider to specify where the custom fingerprint is inserted into the content or where the fingerprint is to replace a placeholder within the content.