In the case of Cesarini v. United States, decided in 1970, the court addressed the issue of whether a taxpayer could claim a refund for taxes paid on income that was later determined to be non-taxable. The case involved a couple who discovered a stash of cash in a piano they purchased, which they initially reported as income. The court ruled in favor of the taxpayers, stating that the money found was not subject to taxation because it was not earned income. This decision clarified the treatment of unexpected income and the conditions under which taxpayers could seek refunds for previously reported income.