Elmer Tiling Cunningham (September 1, 1889 – June 14, 1965) was an American entrepreneur and businessman, specializing in vacuum tubes and radio manufacturing. He is best known for being the most successful business person to produce counterfeit (AKA bootleg) or unlicensed vacuum tubes (1915-1920). Cunningham was in direct violation by infringing on the Fleming and De Forest vacuum tube patents. Unlike other businesses making unlicensed or bootlegged vacuum tubes, Cunningham was very aggressive in his advertising. Manufacturers of counterfeit vacuum tubes generally ended their activities after a lawsuit has been filed but Cunningham came out ahead after various lawsuits brought against him and his company, the Audio Tron Sales Company. His successes encouraged many others to do the same thing.