This term doesn't sound right to me. I mean, I agree that there are atheists who are preachy about their beliefs and actively try to convince people that their religion is wrong. But this activity isn't practicing atheism, it's preaching rationalism or enlightenment morality/philosophy.
Atheism is the lack of a belief, it is not a positive belief or the basis of a worldview, nor is it something to actively "practice."
Also, you can be a "practicing Muslim" or a "practicing Christian" without trying to convert people.
That was a darn good post. I would add further that Atheism is not a belief in the sense that there are no practices, customs or rituals. For instance, someone could not have ever heard of a theistic model. They are atheist by definition but have no active belief.
There are two worldviews: the one that establishes reality as all encompassing and has no need for the supernatural realm. This is the "rational" (within the bounds of reason exclusively) worldview.
The other view, the theistic view, asserts that reality requires a supernatural causation; thus, the supernatural --and less diplomatic sounding-- "irrational" (outside the bounds of reason exclusively) worldview.
And please note these conventions have nothing to do with the common ideas that a rational person is a well thought out person and an irrational one is a chaotic maniac. These are philosophical conventions, nothing more.
Both the theist and the materialist require some level or faith or trust (respectively) in order to believe their worldviews are reality. The theist's theological faith is an acceptance of the existence of a divine being who via supernatural means establishes all of reality including the laws of nature and logic which allow for the existence of knowledge. The materialist relies on a
priori logic that states that reality is self-caused, and empirical events allow for the existence of knowledge. For myself, I don't conceive of my atheism as a belief as much as I conceive it as a conclusion based on the asserted models out there and the lack of evidence to support those assertions. As an example, one can't really consider oneself as having the "belief that Santa doesn't exist". It's just a fact-- Santa doesn't exist, and only those who would assert he does are required to support the claim with evidence.
Until then, Gods, Demons, Jinn, etc., remain an unsupported, untested and unproved assertion that even those who embrace it admit cannot really be explained or defended.