This past May, a Venezuelan state TV host announced he had discovered a conspiracy to assassinate the elder brother of President Hugo Chavez.

His evidence? A newspaper crossword puzzle.

He pointed out that the crossword contained the word asesinen (“murder”), intersecting horizontally with the name of Chavez’s brother, Adan. And directly above the name was the word ráfagas, meaning either “gusts of wind” or, more ominously, “bursts of gunfire.”

David Kahn, an American historian and journalist, would call this a classic example of the “pathology of cryptology.” In his seminal 1967 book, The Codebreakers, Kahn marveled at the ability of individuals to discover incredibly complex, albeit nonexistent codes, which he described as “classic instances of wishful thinking” caused by “an overactive cryptanalytic gland.”

“A hidden code can be found almost anywhere because people are adept at recognizing and creating patterns,” says Klaus Schmeh, a computer scientist specializing in encryption technology. Schmeh has updated Kahn’s research, documenting dozens of bogus or dubious cryptograms. Some are more than a century old, but still making the rounds in books and on websites; others are more recent, such as a claim that all barcodes contain the satanic number, 666.

Amateur sleuths are driven in part by the knowledge that steganography—the art of hiding messages—has long been practiced. A 1499 novel, Hypnerotomachia Poliphili, believed to have been written by a Dominican monk, contains his guilty confession of love for a woman. The book used the first letter of its 38 chapters to spell out the Latin phrase, Poliam Frater Franciscus Columna Peramavit (“Brother Francesco Colonna loved Polia tremendously”). Centuries later, during the Boer War, Robert Baden-Powell, a British officer and artist (and founder of the Boy Scouts), pretended to be a traveling naturalist and embedded maps of enemy military emplacements within his drawings of leaves and butterfly wing patterns.

Schmeh says misguided cryptologists tend to believe that spectacular sources yield the most spectacular revelations. Since the 1850s, perfervid sleuths have been scrutinizing Shakespeare’s plays, claiming to have found ciphers denouncing the bard as a fraud and proclaiming the true author to be Sir Francis Bacon. Generations of investigators have been convinced that—through divine revelation or the assistance of extraterrestrials—the builders of the Great Pyramid embedded the sum total of scientific knowledge within the dimensions of the structure. Fringe pyramidologists persist in their claims despite a 1992 effort to debunk them by Dutch astrophysicist Cornelis de Jager, who demonstrated the dimensions of any object can be manipulated to yield a desired outcome; he derived the speed of light and the distance between the Earth and Sun from his measurements of a bicycle.

Still, amateur codebreakers take their work seriously. According to British psychologist Tomas Chamorro-Premuzic, who has studied personality profiles of conspiracy theorists, “They are altruistic,” since they think that they’re uncovering truths hidden from the public. For them, believing is seeing.