It is their right, And if they feel this is a way to be heard, It is right, Even if it is loathesome. So long as they obey all relevant laws in their efforts, So be it. Always remember when you wish to curtail a freedom, Act towards your target as if you were your target wishing to curtail YOUR view.
The other day I heard that in Iowa, a religious group of people from Arkansas from all places, went to a veteran's funeral and slandered our veterans as a whole. They were also known to have trampled on the American flag, and that's how it got some national coverage, when the law enforcement arrested one or some of them for trampling the flag ( I haven't confirmed that yet). Of course, they can not be tried for that because according to the supreme court, flag burning and the like is a form of free speech protected under the 1st amendment. But in my opinion, aside from the flag desecration, I believe these guys should burn in hell for not only for slandering a dead hero but also for defying the laws of their own bible.