Isn't it vice-versa? It's hard from a legal point of view to spy on one of your own, but it's easier to do it on a foreign entity?
> During the 2013 NSA leaks Internet spying scandal, the surveillance agencies of the "Five Eyes" have been accused of intentionally spying on one another's citizens and willingly sharing the collected information with each other, allegedly circumventing laws preventing each agency from spying on its own citizens.
> During the 2013 NSA leaks Internet spying scandal, the surveillance agencies of the "Five Eyes" have been accused of intentionally spying on one another's citizens and willingly sharing the collected information with each other, allegedly circumventing laws preventing each agency from spying on its own citizens.
[0]: https://en.wikipedia.org/wiki/UKUSA_Agreement#Controversy