This is Internet dear! Here I have seen people who propagate the most henious of acts/comments against Islam and Prophet (PBUH). You and me can do nothing more than belittle thier comments, teach them what true Islam is, ignore their mis-deeds and comments and move forward. The best response is to be a role model of Islam and follow what prophet (PBUH) taught us. These critics and ignorants would soon find themselves isolated, humilated, down and out!