The Pseudonym: A Great American Tradition

"During the eighteenth century, it was common for writers and journalists to use pseudonyms, or false names, when they created newspaper articles and letters to the editor. Franklin used this convention extensively throughout his life, sometimes to express an idea that might have been considered slanderous or even illegal by the authorities; other times to present two sides of an issue, much like the point-counterpoint style of journalism used today."

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(From that I infer that Mr. Franklin probably even wrote things some people found annoying.)