By reviewing DRMs up to now and two typical examples – AVS DRM and DMP IDP, the paper tries to find out the fundamental challenge of content protection approach from technical and social viewpoints. Not only it is difficult to deploy and update content encryption and security infrastructure, but also the content diffusion is limited and Fair Use is affected. The new schema for DRM should content monitoring system in public space that prevents illegal diffusion of content in copyright but permits content being used freely in private space or for social liberty. The traditional rights in analog times will fluently move to digital space under the proposed schema.