Update: Red State has admitted this is a hoax:
Firefox users: We sent you a little message today.
By: The Directors (Diary) | April 8th, 2014 at 06:41 PM | 74
Today, users of the Firefox web browser were given a message when accessing most of our Front Page content at RedState. They were told that this site could not be displayed, because of a conflict with the values of the Mozilla corporation, and they were suggested to visit another site.
We put that message up, because we wanted to remind people that the totalitarian impulse of the Mozilla corporation is real, and if you haven’t been Made to Care yet, you will be soon.
Send a message that you won’t take it lying down. Get another browser.
I deeply regret passing along a hoax, and am angry at Red State for publishing something that is untrue. Red State has lost my respect and any future presumption of credibility. They may also be hearing from Firefox's attorneys. This is an excellent way to scarifice a good cause in the name of sensationalism. Much though I hate it, I must hereby apologize to Firefox, and I blame Red State.
-Thomas Lifson, editor
http://www.americanthinker.com/blog/2014/04/firefox_expands_into_censorship.html
I don’t think there’s anything for this guy, or for RedState, to apologize for. The “hoax” was well founded and intended.
I still use Firefox (am shopping around for alternatives), but think that having Conservative websites cut off access to Firefox users for a day or two in order to call attention to this fascism, would be just fine.
“It was a hoax (but drop Firefox anyway):”
I thought it was pretty obvious it was a hoax...
See, I actually get jokes on the web.