A good quote via Neil Addison at his Religion Law Blog.
Free speech includes not only the inoffensive but the irritating, the contentious, the eccentric, the heretical, the unwelcome and the provocative provided it does not tend to provoke violence. Freedom only to speak inoffensively is not worth having.
So said Lord Justice Sedley.
Unfortunately there are people about who would like to shut down debate by means fair or foul on certain subjects.