Many of us wouldn't agree with the GB PM on an awful lot of issues, but Mr Cameroon does hit the nail on the head when he says that there is a right to cause offence as long as it stays lawful (presumably keeping this side of incitement to hatred laws).
This is what he says...
"... Mr Cameron replied: "I think in a free society, there is a right to cause offence about someone's religion.
"I'm a Christian - if someone says something offensive about Jesus, I might find that offensive, but in a free society I don't have a right to, sort of, wreak my vengeance on them."
He said as long as publications acted within the law, they had the right to publish any material, even if it was offensive to some. ..."
http://www.bbc.co.uk/news/uk-30869585