In fact, real atheists probably would have nothing to do with this, they tend to be much more reasonable to deal with, and respectful of others’ beliefs, but these people definitely have a huge axe to grind.
Soviet Union:
The League of Militant Atheists, AKA Union of Belligerent Atheists or Society of the Godless
Their slogan:
“Struggle against religion is a struggle for socialism”
http://en.wikipedia.org/wiki/Society_of_the_Godless