DMCA guidelines for Transparent Proxy Caching

DMCA stands for Digital Millennium Copyright Act. Section 512(b) of DMCA limits the liability of service providers for the practice of retaining copies, for a limited time, of material that has been made available online by a person other than the provider, and then transmitted to a subscriber at his or her direction.

More details can be found at http://copyright.gov/legislation/dmca.pdf

DMCA provides guidelines for Service Providers in United States, who would like to deploy a caching solution. Service Providers from other parts of the world, also expect their caching solution to be fully DMCA compliant.

The following are limitations imposed by DMCA:

• The content of the retained material must not be modified.
• The provider must comply with rules about “refreshing” material— replacing retained copies of material with material from the original location— when specified in accordance with a generally accepted industry standard data communication protocol.
• The provider must not interfere with technology that returns “hit” information to the person who posted the material, where such technology meets certain requirements.
• The provider must limit users’ access to the material in accordance with conditions on access (e.g., password protection) imposed by the person who posted the material.
• Any material that was posted without the copyright owner’s authorization must be removed or blocked promptly once the service provider has been notified that it has been removed, blocked, or ordered to be removed or blocked, at the originating site.

DMCA does not outline how a service provider can adhere to the above guidelines. Different service providers/caching vendors use different mechanisms to adhere to the above guidelines.