 Among the longest-standing and most widely recognized conspiracy theories are notions concerning the assassination of John F. Kennedy, the 1969 Apollo moon landings, and the 9/11 terrorist attacks, as well as numerous theories pertaining to alleged plots for world domination by various groups both real and imaginary.Scholars argue that conspiracy theories once limited to fringe audiences have become commonplace in mass media, contributing to conspiracism emerging as a cultural phenomenon in the United States of the late 20th and early 21st centuries.The general predisposition to believe conspiracy theories cuts across partisan and ideological lines.