 Following the Act of 1819 , in 1820 the Court began to distinguish Palmer . In United States v. Klintock ( 1820 ) , the Court distinguished Palmer — in a case involving piracy by a U.S. citizen , claiming to act under the authority of the Mexican Republic , committed against a Danish ship and citizens , under the fraudulent claim that the Danes were Spanish ( Spain being at war with the Mexican Republic ) — on the grounds that the victims in Palmer were not subjects of a nation recognized by the United States . In United States v. Furlong ( 1820 ) , sometimes referred to as United States v. Pirates , authored by Justice Johnson ( a dissenter in Palmer ) , the Court distinguished Palmer again , primarily on the ground that the pirate vessel had no nationality ( it was an American ship prior to being hijacked ) . United States v. Holmes ( 1820 ) distinguished Palmer on the same ground , further holding that the burden was on the defendant to prove that his vessel flew a lawful flag . 
