Why are the religious so sensitive?

[Darwinian]

After watching part one of 'The Four Horsemen' yesterday an interesting point was raised about how deeply offended and angry some religious people get when you question their faith and how society seems to treat religion as somehow more important than other subjects.

For example, if I wrote a book directed towards how strange and pointless I though the whole world of football was, it would certainly get a reaction from football fans but I doubt very much if it would be met with the kind of vitriol, aggression, death threats and emotional outpouring that ensues when books like 'The God Delusion' are released.

The question is, why does religion have this special status where it is generally seen as a terrible taboo to mock, question or even challenge these beliefs?

And it's not just the faithful either, there are even examples of protecting these sensibilities by proxy. I am thinking of such things as organisation banning decorations and trees in their shops at Christmas because it might offend Muslims or Hindus etc. which of course it would not and in many cases does these groups no favours as it simply exaggerates societies perception of extreme sensitivity.