I haven't read any Dan Brown novels. I haven't seen the movies either. I've read and listened to a lot about them though. I searched my archives and I actually made a post about Dan Brown and The DaVinci Code once. Dan Brown's books make some claims as to the accuracy of the history, rituals, and other claims made in these best-selling fictional books.
The London Telegraph took on some of the claims in Dan Brown's books. They examine 50 factual errors in these books.
Maybe one day I'll read the books. I hear they're good. Heck, two movies have been made out of them. I don't have anything against the books; I've just had other priorities.