What makes Americans think they can insult Islam and the name of Mohammed without there being consequences?

They don't. They know that if an unremarkable pastor from a small church in Florida burns a few Korans, gangs of Muslims will take to the streets calling for death to the west, swivelling their bulgy eyes all around and making that vulgar, braying chant of 'Allahu Akbar!'. Or worse. Trust me, the whole world from the southern tip of Chile right up to the north eastern tip of Russia knows. We are not amused, sir!