If the storyline of your novel bears an unhealthy resemblance to another author's work, then a book promotion campaign could land you in court for plagarism. That's what this article suggests.
Call me skeptical, but I doubt that anyone is purposely ripping off anyone else's work. You know the old saw about all those monkeys and all those typewriters . . . well, that's probably the way two writers's works wind up with the same plot points once in awhile.
Does that warrant a lawsuit? No, I don't think so. It would be a shame to miss such thought-provoking reads as "The Da Vinci Code" just because some other author/researcher had developed a similar theory about something that happened two thousand years ago to the one Dan Brown came up with.
Writers, writers. Can't you all just try to get along with each other?