this is just another reason that people have thought of to point the blame at atheism..especially I have found out, when you talk about events like the crusades, witch hunts or the inquisition. Personally, I'd hardly call us even...even if we DID kill in the name of our lack of belief.

there has been communist leaders who did not have faith in a god or religion, who have killed countless people for not thinking like them. But, was it because of atheism that they did this?

First, you have to understand that atheism is not a belief system. There are no Atheist principles or philosophies. I read a great quote once that said: "Being killed by an atheist is no more being killed in the name of atheism than being killed by a tall person is being killed in the name of tallness."

Some of the reasons these rulers were responsible for the deaths of people that disagreed with them is because they did not agree with those in power. Some were anti-communists and opposed the government. The main reason, is because these people got in the way and were inconvenient for the corrupt rulers.

Most of the reason people were killed were because of political reasons. Atheism is simply the lack of belief in a higher being.

The reason people would kill for a belief system in the first place is because of the doctrines that are followed, atheism however does not have any doctrine...so it couldn't possible be used as a credible reason for bad people to do bad things.