There's also a legal component of control. More DRM means more identifiers for content creators, distributors, consumers, including open-source Firefox that will support HTML5 DRM.

http://www.michaelgeist.ca/2014/10/new-tpp-leak-canada-emerg..., ".. shows Canada as the strongest opponent to TPP IP demands, signalling its opposition to a proposal 56 times, more than any other country. The strongest opposition comes in the patents, enforcement, trademarks, and copyright sections.

.. the U.S. wants Canada to eviscerate many of the recent reforms found in copyright and counterfeiting legislation along with court rulings on patent protection. These demands focus on enhanced criminal liability for copyright infringement .."

As far as I know the DRM on DCPs (Digital Cinema Package) isn't broken. Yet. Maybe because relatively few people have access to the encrypted content. I guess the most important thing for the movie industry is to have the cinema window free from pirated copies.

Where/how is this used? I ask because screeners are definitely a thing.

Most digital cinema releases are AES 128 bit encrypted. For specifics refer to the DCI specification [1].

Screeners are from DVD/Bluray copies sent to academy members and such? If I'm not mistaken?

[1] http://dcimovies.com/specification/DCI_DCSS_v12_with_errata_...

DCP is the format in which movies are distributed to theaters, usually on hard drives but sometimes over satellite or wired networks.