The "implementation" of an interface is the code that actually does stuff when that interface is called. In this case, the implementation of the DRM hooks are

The "implementation" of an interface is the code that actually does stuff when that interface is called. In this case, the implementation of the DRM hooks are those proprietary DRM modules. This "standard" shuts everyone except the select few in the dark. Without have the appropriate plug-in, you cannot access the content.