Mental health warning, indeed

[mdlbear]

I can't decide whether the organization described in this article from Ireland Online is misguided, stupid, or willfully ignorant, but they appear to be completely serious.

A group of Christians determined to address what they claim are the myths of The Da Vinci Code are to offer the Irish public a mental health warning on the film before it hits cinema screens.

Hope Ireland, made up of Catholics and Protestants, will run an information campaign in a bid to expose author Dan Brown\u2019s best-seller as nothing but cunning fiction.

The group, supported by Church of Ireland and Catholic clergy and members of the secretive Opus Dei organisation, claims The Da Vinci Code does not know where the boundaries between truth and invention lie.

Which part of "fiction" didn't they understand? (From Gary McGath.)