Conservatives have sought to portray the plan to build an Islamic cultural center near Ground Zero as a kind of end-zone dance on the part of Muslims worldwide, a celebration of the deaths caused by the 9/11 attacks. This doesn't really make much sense -- the organization building the center, the Cordoba House, is a moderate organization, and its leader, Imam Faisal Abdul Rauf, is known for his attempts to reconcile being a Muslim and being American. The necessary conclusion that one draws from the conservative argument is that there's no distinction between average Muslims and terrorists.
A number of false rumors have been spread to reinforce the idea that the center is a symbol of Islamist triumph over the United States, such as the unsubstantiated charge that Rauf has ties to the Muslim Brotherhood, or the equally unsubstantiated accusation that the center will be funded by extremists. Media Matters has found another one -- the rumor that the center itself will be unveiled on September 11, 2011. The rumor has spread all over the right-wing media, but here's an example from Fox:
On the July 19 edition of Fox News' Fox & Friends, co-host Alisyn Camerota said of Park 51, a Muslim community center and mosque set to be built two blocks from the World Trade Center site: "It's not just the location, by the way, that has people outraged ... some of the dates that the mosque plans to celebrate, even the opening dates, so there's a lot here." When co-host Brian Kilmeade asked her, "You mean 9-11?" Camerota replied, "9-11, that is when they plan to launch, yeah."
According to Cordoba House, it just isn't true. But you can see why it's spread so quickly -- in order to justify opposition to the project based on nothing more than the religion of the builders, some connection between them and the terrorists who attacked America has to be manufactured. Otherwise the intolerance at the heart of the controversy is laid bare.