Atheists not allowed to join FreeMasonry

[Pizza]

There was a reddit AMA (ask me anything) thread once where an atheist freemason said it really depended on the lodge you joined, and that some of them were fine with atheists who believed in "a power greater than themselves". He said that in his case, he believed that a bear would be more powerful than him, so technically he met the requirement.
Freemasonry is more of a social group than a religious order though; I think the main reason for atheists joining would be that their family were already members. Whilst I'm not a freemason, my paternal grandfather was a grand master (I have some of his masonic documents in a safe) which is quite interesting.

This doesn't surprise me.  Supreme Being and higher power are vaguely defined and I imagine most masons just don't care since if I remember correctly they aren't allow to talk about religion and politics at the lodge.