Before the adoption of public international law, pirates and slavers were generally held to be beyond legal protection and so could be dealt with by any nation, even one that had not been directly attacked.
As the summary punishment, in this case, was due to military necessity, there was clear evidence of the offense, and it was done proximate in time and location to the battlefield, it can be classified as merely irregular, and not a violation of the custom of the sea.
[6] Other commentators, such as John Yoo,[7] have called for the extension of this hypothetical connection of hostis humani generis from pirates to hijackers to terrorists all the way to that of "unlawful enemy combatants".
In deciding this, the court famously stated that "Indeed, for purposes of civil liability, the torturer has become like the pirate and slave trader before him: hostis humani generis, an enemy of all mankind."
This usage of the term hostis humani generis has been reinforced by the ruling of the International Criminal Tribunal for the Former Yugoslavia in the conviction of a torturer in Prosecutor v.