Park51 is the name of the mosque project being built near ground zero. Naturally it has garnered much opposition. Just do a Google search for Ground Zero Mosque and you'll see the vast number of anti-mosque news pieces and blog entries.
Of course, the argument is that the Muslims are proclaiming their victory by building a worship center at the site of their accomplishment (never mind there was a mosque there prior to 9/11 and it was destroyed in the attack).
I had this thought yesterday: For those who oppose a religious group re-opening their community center, do you also oppose Christian organizations opening churches in Iraq or Afghanistan?
Let's be consistent. If we don't want the Muslims to build a community center at the site of their supposed "victory," why do we support building churches in those two nations we invaded and conquered?
Treat others the way you want to be treated. Somehow, I think Jesus' words shouldn't just apply to Sunday morning.