Freedom of speech is a powerful tool. It can unite people, it can split people, and it can, in this case, become an example of religious strife. Without the very freedom of speech the man in this picture would not have been able to make his views known to the world, and others would not be able to disagree with him.
When one looses their freedom of speech then that is oppression. It is oppression that leads to ignorance of the issues and enlarges the fissure of intolerance.
Freedom of speech allows for polite and informative discourse. Increasing the diversity of ideas, the very purpose that our Founding Fathers found important.
Picture from http://www.photojournal.co.uk/timothy_allen_photographer_photos/timothy%20allen_extreme%20irony.jpg