I've been irritated by the false information being spread by the media (2 instances on cbc) in relation to The Da Vinci Code. In an interview on The Current (scroll to part 3, "Shadow People") someone described as an "expert on secret societies" purported that in the book Christ hadn't died and had children with Mary Magdalene. This is not the case - in The Da Vinci Code after His crucifixion Mary and His daughter Sarah are taken to France.
I expect someone who is commenting on the book to have (at the least) read it; conjecture doesn't count.
He may have been an expert on secret societies, but it was hard for me to really believe anything else he said fully when he opened with something that I knew was untrue.
In addition, the cbc article on Opus Dei claims that: "Brown's novel paints the real-life religious organization as a sinister Catholic cult, embodied by the book's villain, Silas. Brown depicted Opus Dei as a secretive, powerful and murderous sect, whose members whip themselves bloody. Members of Opus Dei say their portrayal in the book is a mistaken and exaggerated caricature."
This is at best a half truth. In the book, Silas is working under the direction not of Opus Dei but of The Teacher who has made an arrangement with Bishop Aringarosa. As well, The Teacher had promised him that there would be no killing. Silas isn't the villan of the book either - he's a pawn of The Teacher.
But, this would require actually reading the book.