People are going to go along with this for a lot of stupid reasons, first among those to simply irritate others for no good reasons, but there are many great reasons to show support for this.
If you support this do it for freedom of expression, do it to show that you will not be threatened by religious extremism, and do it to show that simple religious beliefs are not worth fighting and dying for in this country.
Although the Catholic church may have a lot of blood on their hands in the past I did not see the church or any organization threaten violence when Matt and Trey showed a statue of the virgin Mary spew vaginal blood all over the pope.
And that's what is important here, to say you have the right to be offended, you have the right to boycott the show if you wish or to persuade others with non-violence to not watch the show, but the moment you use threats, violence and terrorism to try and get your way you've crossed a line.