So I present the obvious: Why not build a mosque near the hallowed grounds of the WTC? American Indian holy sites are desecrated by Christians all the time.
This is a subset of the white privilege and power that most whites are oblivious to--except when they feel threatened. Who decides which Indian treaties and rights are still valid? Which people are made into sports mascots or cast in Native movies? Which stereotypes are socially unacceptable and which are okay? White Christian Euro-Americans, the same people who have dominated and controlled the land for almost 400 years.
For more on our prejudice against Indians, see Muslim "Tribes" = Indian Tribes?! and Yesterday's Cherokees = Today's Muslims. For more on the subject in general, see Conservative Rallies = White Self-Pity and Tea Party Believes in Taking.
Below: Because it's about white people, sacred:
Because it's about Indians, not sacred: