Free Speech in the United States

For those of us who live outside the United States this can be difficult to understand.
 
Free Speech and freedom of Religion are guaranteed in the U.S. Constitution by this. 

The First Amendment
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.

The part on religion states that the government cannot and shall not create a State Religion.
Religion and religious beliefs are the sole providence of the individual citizen.  Meaning you can practice and hold beliefs in any religion without prohibition of the government. 

Freedom of speech means exactly what is written: That no matter how offensive your speech may the United States government is prohibited  from infringing upon that right.  
Simply put the makers of the anti Muslim film have broken no laws and cannot be prosecuted.   

As offensive as that film my be there are no blasphemy laws in the United States because of the First Amendment to the United States Constitution.