What is this man's actual crime? We know what this crime is under Islamic law (sharia), "do not insult Islam," but what is the crime in the West? We are not subject to imperatives within the Islamic faith.
Qur'an burning is a stupid idea, of course, but is protected under the laws of free speech. The burning of books is wrong in principle: the antidote to bad speech is not censorship or book-burning, but more speech. Open discussion. Give-and-take. And the truth will out. There is no justification for burning books. If free men are to be free and not live under Islamic law (sharia), then this man can do this if he wants, and his freedom and rights should be protected. Islamic supremacists should not be allowed a victory for their violent intimidation -- if these people want to burn a book, they're free to do so.
"The principle of free speech is not concerned with the content of a man's speech and does not protect only the expression of good ideas, but all ideas. If it were otherwise, who would determine which ideas are good and where forbidden? The government?"
"Once a country accepts censorship of the press and of speech, then nothing can be won without violence. Therefore, so long as you have free speech, protect it. This is the life-and-death issue in this country: do not give up the freedom of the press -- of newspapers, books, magazines, radio, movies, and other forms of presenting ideas. So long as that's free, a peaceful intellectual turn is possible." Ayn Rand.
If this is unlwful, what next? Anything and everything that insults Islam? Then no one will be able to leave their homes eventually, except the truly pious Muslims. That is the eventuality. That is the road we are on. That was the reality for non-Muslims living under Muslim rule for over a millennium. Just look at countries currently living under Islamic law. This is a very slippery slop.