Atheist sites at this school=blocked. Why?

Why the HECK (pardon my strong language) are "alternative spirituality" sites which have information about and/or promote atheism, Wicca, agnosticism, Satanism, and "magic and paranormal" blocked? This is a rather blatant violation of the Establishment Clause, as it prefers one religion over another and it prefers religion to irreligion. While I can understand why one wouldn't want websites about Satanic Ritual Abuse (SRA), I can't see why sites about atheism are blocked! I attempted to get on that site for a genuine research paper, but it was censored. So, this school is actually reducing the quality of their student's schoolwork by doing this. Are they afraid that students will convert to such beliefs? Well, if they keep this up than they should be. Oliver Wendell Holmes discussed the "marketplace of ideas" saying that if an idea is allowed to be discussed, than the people will judge it as a good idea or a bad idea. However, if a bad idea is censored, the people who have it will say "Well, if this is such a bad idea, why is the government afraid that we will take over?". If the school is really so concerned about students converting to atheism and think that it's such a bad idea, they should allow for open research of it from a pro-atheist standpoint as well, or else students will wonder why the school is so afraid of it. In fact, many of our founding fathers and early presidents were irreligious, although few were atheists. Abraham Lincoln himself did not profess any religion. To teach our Founding Fathers as heroes (which they were), but to discriminate against the irreligious and say that "Our nation was founded on Judeo-Christian beliefs." is tantamount to saying that our nation was founded on Muslim values. Either block all religion websites or (preferably) none. It is unconstitutional to have it both ways.