That is what The Da Vinci Code is, a calumny. That is why Opus Dei is upset. The book starts with a prologue entitled FACT which ends with this sentence I copied and pasted so many times "All descriptions of artwork, architecture, documents and secret rituals in this novel are accurate". The problem is not that the descriptions of the artwork are inaccurate, or the architecture he describes is false, the problem is that the 'secret rituals' attributed to Opus Dei are false. Is a calumny directed to this christian organization that damages their reputation. That is why they are not happy. I wouldn't be happy either if somebody keeps telling lies about me. I would be very upset.