When is enough, enough? First Amendment vs. Ground Zero?

If we searched the religious backgrounds of all who died at the sight of the 9/11 attacks, we might find many beliefs from all over the world. The World Trade Center was just that, a 'World' trade center - that brought many people together, from all corners of the globe... working harmoniously in chosen careers. Maybe a interdenominational monument or statue or a recognition of lives who lived. But lets keep the politics of religion away from that hallow ground... a mosque, seriously??