I've already ranted a few times about EME and how it's bad and all that. In this post I want to point out one specific aspect, how EME can be used to exclude users to content based on their software and/or hardware choices.
Quick brief, EME is nothing without CDM. CDM is the blackbox part that is not part of the W3C's specifications. It is delivered to the user either by being a downloadable element, like a plugin, it can be bundled in the browser, or in the OS.
CDM can also be in form of hardware.
I've already brought up the point that users on non-mainstream setups will almost certainly be excluded by websites using EME. How many CDMs will be compatible with FreeBSD on ARM ?
Those who publish using EME will need to use one or more CDMs. If a publisher wants their content to be available to the most possible platforms, it will cost them more to have their content managed by as many CDMs possible. Yet this will still never guarantee 100% compatibility with all systems that have implemented all of the W3C's recommendations.
Again, a browser + operating system + hardware that support all and any element in all versions of the W3C's HTML does not mean it can view any content published using that same set of recommendations.
The outcome might be 2 things, some organisations may have to chose which platforms they can afford to support, other organisations may chose to explicitly exclude certain platforms by choosing which CDMs to employ. In other words, the motivation to support more or less CDMs can range from budget to malice and anything in between.
A possible option is to use only a specific hardware CDM, which means that content published using EME could potentially only be accessible using a specific device and hardware CDMs are already in the works.
An example would be, if Apple implements hardware CDM in their new devices, they could publish content that can only be decrypted by their own devices. In this same way, it can be possible to allow access to content only to those who have purchased a chip that needs to be installed in to their computers. This implies many other problems, related to security and privacy, that's another story.
The conclusion here is that EME will allow web pages to be 100% W3C valid while expclicity excluding access to users based on their choice of software and/or hardware. The publisher will have the possibility of deciding which platforms may access their content. The instant EME becomes an actual W3C recommendation is the when the W3C no longer respects their own principles.