Mozilla doesn't have a choice. Let's say Firefox has 30% of users. The argument is that sites will not use DRM, because they'll be losing revenue from 30% of their users, and therefore Mozilla saves the day.

But, what happens if Google says they'll accept that challenge, and they're willing to lose 30% of revenue from something like YouTube in the short term. They implement DRM on YouTube, and Firefox users can no longer watch videos. What happens? Firefox users start converting over. Where to? Chrome, which falls into Google's best interest. Now, that 30% loss keeps getting smaller and smaller, and Chrome users start increasing. Fast forward a year, and Firefox only has 10% of the users. This continues to shrink until Firefox dies.

Sadly, this is what happens when we give Google and Facebook too much power, and the ability to run the internet. It's our fault for giving them that position, and not developing or supporting alternatives. If you want to fight back, you need to give Mozilla a better position to stand. Sites like Wikipedia, Imgur, etc, need to run banners for browsers that support DRM, and block users, or encourage them to switch to a DRM free browser, like Firefox. Take the wind out of their sails, before they try to do the same to us.