Cheek v. United States, 498 U.S. 192 (1991), was a United States Supreme Court case in which the Court reversed the conviction of John L. Cheek, a tax protester, for willful failure to file tax returns and tax evasion. The Court held that an actual good-faith belief that one is not violating the tax law, based on a misunderstanding caused by the complexity of the tax law, negates willfulness, even if that belief is irrational or unreasonable. The Court also ruled that an actual belief that the tax law is invalid or unconstitutional is not a good faith belief based on a misunderstanding caused by the complexity of the tax law, and is not a defense. Background The defendant, John L. Cheek, became a pilot for American Airlines in 1973. Through the tax year 1979, Cheek filed Federal income tax returns. Beginning with the 1980 tax year, Cheek stopped filing Federal income tax returns. He began claiming up to sixty allowances on his Form W-4 withholding statement submitted to his employer. From 1982 to 1987, Cheek was also involved in at least four civil cases challenging the Federal income tax. Among the arguments raised in those cases were: (1) the argument that he was not a taxpayer within the meaning of the law; (2) the argument that wages are not income; (3) the argument that the Sixteenth Amendment does not authorize an income tax on individuals; and (4) the argument that the Sixteenth Amendment is unenforceable. In all four cases, the courts stated that these arguments were erroneous. Cheek also attended two criminal trials of individuals charged with tax crimes. John Cheek himself was eventually charged with six counts of willfully failing to file Federal income tax returns under for 1980, 1981, 1983, 1984, 1985 and 1986. He was also charged with tax evasion under for years 1980, 1981, and 1983. Trial court At his own criminal trial, Cheek represented himself. He also testified that around 1978 he had begun attending seminars conducted by a group that believed that the Federal income tax system was unconstitutional. Cheek stated that based on the seminars and his own study, he sincerely believed that the tax laws were being unconstitutionally enforced, and that his actions were lawful. Cheek specifically testified about his own interpretations of the U.S. Constitution, court opinions, common law and other materials. He testified that he had relied on those