After the September 11, 2001 terrorist attack, the Rev. Jerry Falwell remarked that the ACLU, by trying to "secularize America," had provoked the wrath of God, and therefore caused those terrorist attacks. (Falwell later apologized for the remark.) Other critics of the ACLU do not make such strong accusations, but claim that the organization pushes the concept of separation of church and state beyond its original meaning. The ACLU and Jerry Falwell sometimes find themselves on the same side. Notably, the ACLU filed an amicus brief supporting a suit by Falwell against the state of Virginia. The suit, which was successful, overturned the Virginia constitution's ban on the incorporation of Churches. In addition, the ACLU has defended the rights of a Christian church to run anti-Santa ads on Boston subways, the rights to religious expression by jurors, and the rights of Christian students to distribute religious literature in school.[24]
So basically Falwell blamed 9/11 on them and they still defended his rights. There whole point is to keep church and state seperate, but they still defend the rights of religious groups, even christians.