Even relatively benign ones like this. I am a fan of Paul McCartney so I was intrigued to stumble on a page (through a search engine) where all the contributors referred to Sir Paul in the past tense, and also referred to someone called "Faul".
I really should have guessed what it was all about, as you doubtless have, but this paragraph (from the "About" section) explains:
The "official" PID story says Paul was killed in a car crash November 9, 1966 and was replaced by look-alike William Campbell or Billy Shears. Although the "car crash" story is probably bogus, two forensic scientists proved Paul was replaced in 1966 by conducting a biometrical analysis of Paul pre & post 1966. Their finding appeared in an article entitled "Chiedi chi era quel «Beatle»" in the August 2009 Italian issue of WIRED magazine. Physical differences that give the double away include differences in the jaw line, lips, teeth, palate, nose, nasal spine, ears, tragus, eye color, and skull shape (please see this article at the Plastic Macca blog for more information).
Paul's impersonator has been dubbed Faux Paul and Bill by the other Beatles. They referred to him at the beginning of the song, "A Little Help From my Friends" on the Sgt. Pepper album as "Billy Shears." This could mean "Billy's here," or potentially be a reference to William Shakespeare, who has been said to have been a pen name for Sir Francis Bacon. George and John referred to "Beatle Bill" in the movie, "Imagine: John Lennon."
I love the fact that the Baconian theory of Shakespeare's works is dragged into it. A few lines down, the Illuminati make their almost inevitable appearance. It's as though all conspiracy theories touch fingers at a certain point. (I also like the contrast between the "official" Paul is Dead story, which is "probably bogus", and the true one. Conspiracy theories about conspiracy theories!)
G.K. Chesterton described the pathology of the conspiracy theorist very well in Orthodoxy:
Every one who has had the misfortune to talk with people in the heart or on the edge of mental disorder, knows that their most sinister quality is a horrible clarity of detail; a connecting of one thing with another in a map more elaborate than a maze. If you argue with a madman, it is extremely probable that you will get the worst of it; for in many ways his mind moves all the quicker for not being delayed by the things that go with good judgment. He is not hampered by a sense of humour or by charity, or by the dumb certainties of experience. He is the more logical for losing certain sane affections. Indeed, the common phrase for insanity is in this respect a misleading one. The madman is not the man who has lost his reason. The madman is the man who has lost everything except his reason.
The madman's explanation of a thing is always complete, and often in a purely rational sense satisfactory. Or, to speak more strictly, the insane explanation, if not conclusive, is at least unanswerable; this may be observed specially in the two or three commonest kinds of madness. If a man says (for instance) that men have a conspiracy against him, you cannot dispute it except by saying that all the men deny that they are conspirators; which is exactly what conspirators would do. His explanation covers the facts as much as yours. Or if a man says that he is the rightful King of England, it is no complete answer to say that the existing authorities call him mad; for if he were King of England that might be the wisest thing for the existing authorities to do. Or if a man says that he is Jesus Christ, it is no answer to tell him that the world denies his divinity; for the world denied Christ's.