[Fice]

This is not enough if we don't stop DRM (which Firefox also supports).

DRM essentially means: only allow access with a program that implements certain required measures to restrict user's control over their own computer. Using content decryption blobs to restrict user's access to media streams handled by their own computer — is only a beginning, Web DRM will be eventually extended to allow more restrictions, including those to make it much harder to interfere with the display of ads.