FindLaw informs us that public officials and public figures (including celebrities) have a much higher standard of proof for libel or slander suits than the average Joe, and they have to prove that the alleged slanderer acted with «actual malice.» (chicagopersonalinjurylegalblog.com)
[6] For example, the Committee on the Elimination of Racial Discrimination expressed regret that as a result of «the persisting high standards of proof required for recognition of the relationship between indigenous peoples and their traditional lands,... many are unable to obtain recognition of their relationship to land (art. 5)». (humanrights.gov.au)
In addition, postconviction proceedings impose a much higher standard of proof than do initial trials; courts are extremely loath to overturn jury verdicts. (scientificamerican.com)