"Some people writing on intelligence and surveillance note that close working relations such as this can allow intelligence agencies to evade domestic controls. Jennifer Granick, in her new Cambridge University Press book, American Spies: Modern Surveillance, Why You Should Care, and What To Do About It, notes that Five Eyes countries aren’t supposed to spy on one another’s citizens. However, she says that the NSA has prepared policies that would allow it to spy on Five Eyes citizens without permission. She furthermore suggests that:
The Five Eyes collaboration appears to extend the NSA’s surveillance capabilities, giving the agency a way to spy on Americans without technically breaking US laws that would otherwise prohibit such spying. Edward Snowden described the Five Eyes as a “supra-national intelligence organization that doesn’t answer to the laws of its own countries.” In other words, if US law doesn’t protect the privacy rights of British citizens, and British laws don’t protect the rights of Americans, then they can just spy on us, we’ll spy on them, and our intelligence agencies will just swap information. This evasion of domestic privacy laws would enable essentially unlimited spying unaffected by either collection or usage rules.
Granick notes that if there are rules that would protect Americans from Five Eyes spying, or about the ways that the NSA, FBI or CIA could use information from foreign partners, we haven’t seen them."