Prophet only said
NO! They don't know what they are doing.
What can I say about this young man who killed Van Gogh. His action has not done any good to our Prophet nor to Muslims or Islam. It has not furthered the mission of Prophet which was based on peace and tolerance. I wish today's generation of Muslims understand this. You cannot accuse someone of Blasphemy who does not understand Islam or teaching of the Prophet. There is no use in calling people Blasphemous and punishing them. Only thing these misled Muslims end up doing is they create trouble for Islam and Muslims.
Tolerating a Time Bomb - New York Times: "Last Nov. 2 a young Islamic fundamentalist, born in Amsterdam to Moroccan parents, shot Mr. Van Gogh in the street and then tried to cut off his head. In a final statement at his trial last week, the murderer declared that he had killed Mr. Van Gogh for insulting the Prophet."