It seems to me that the right way to try to decide many political questions, and this is a political question, is to look at it in terms of whether it allows the society using that rule to correct its errors. If Islam is both factually and morally flawed as all other human institutions are, then preventing a specific type of criticism, namely criticism involving pictures of Mohammed, will make correcting the errors of Islam more difficult. There may be other errors involved that are more difficult to correct, like the error that the appropriate response to somebody acting offended at squiggles of ink on a page is to ban the ink squiggles concerned. Finally, I don't buy consequentialism because what counts as a consequence is ambiguous and depends on your theories about the world. For example, I would count damaging our error correcting institutions as a serious consequence of a ban, legal or social, on drawing Mohammed, you would not. So consequentialism doesn't solve the problem, it's just a way of sweeping the real problem under the "consequence carpet".