Here is a fascinating article about the evolution of legal standards in tackling piracy several hundred years ago:

Out of this unfolding of events emerged the Act for the More Effectual Suppression of Piracy, initially introduced by parliament in 1700. This act permitted colonial governments to try and execute pirates on location. (It also eliminated jury trials for pirates, placing their fate in the hands of colonial-appointed commissioners, but continued to permit accomplice testimony). No longer constrained by the need to send pirates to England for trial, the 1700 law proved to be a critically important legal change for bringing pirates to justice.

The initial act was set to expire seven years after its introduction but was made permanent in 1719 when the pirate population began exploding and when various additions to the act, such as rewards for capturing pirates, and punishments for pirate consorters, were also introduced. In 1721 further modifications were made, including a provision for punishing armed merchantmen that refused to fight their pirate attackers.

The effect of these early 18th-century legal changes was to significantly increase the risk, and thus the cost, of pirating after 1719 and 1721 in particular. Whereas only 31% of all pirates hanged between 1704 and 1726 (for which I have data readily available) were hanged in the 15 years spanning 1704-1718, 69% were hanged in the mere seven years spanning 1719-1726 (with the vast majority of these occurring in the years spanning 1721-1726).

This posed a significant problem for pirates because as the legal cost of piracy rose, pirates’ ability to find willing recruits declined, threatening the viability of their criminal enterprise.

Gripping stuff. See also the lively role in all this of C17 newspaper advertisements!

I have posted a Comment there to say that it is not quite clear that these results were achieved by ‘bringing more pirates to justice’.

Surely the (difficult) policy point is that to deal with piracy the quality of justice available to those charged with that offence was watered down to help get convictions?

And the ambitious idea of punishing people who did not fight back against pirates? Try bringing in that law in the context of the War on Terror …