A Christian Atrocity Every Century (Islam isn't the only one to blame)

Christian Americans recently have taken on an air of selective memory and have decided that only Islam represents atrocities and murder and that therefore, all followers of this religion warrant their American rights being stripped as well as their religion insulted.  However, we have to remember that there has not been a single century without an atrocity perpetrated by a Christian as well.  Are we to judge an entire religion for the violence of some of their members?  Should Jews hold Christians responsible because Hitler (a former alter boy) who wrote in Mein Kampf  "I am convinced that I am acting as the agent of our Creator. By fighting off the Jews, I am doing the Lord's work," killed millions of their kin?  Or should African Americans hold Christians responsible because of the estimated 1900+ people killed by the KKK (who claims to be a Christian organization upholding God's law).  Finally, should the native Americans hold Christians responsible because of the trail of tears that killed over 4000 of their number led by President Andrew Jackson (a Presbyterian)?  Or, do we simply look at a bad seed as a bad seed and not blame a whole religious practice for the failures of some in their number?