The UKUSA agreement. The US, UK, Australia, Canada, and New Zealand share Signals Intelligence (SIGINT) with each other and has been used, where country 1 spies on a citizen of country 2, where it would violate the laws of country 2 to spy on its own citizen. Country 1 then provides the collected data to country 2.
https://en.wikipedia.org/wiki/UKUSA_Agreement
Must be fixed. That is horrendous.