The FBI is already having problems here at home with the hacking tool it deployed during its dark web child porn investigation. A few judges have ruled that the warrant used to deploy the Network Investigative Technique (NIT) was invalid because the FBI's "search" of computers around the United States violated Rule 41(b)'s jurisdictional limits.
Now, we'll get to see how this stacks up against international law. It's already common knowledge that the FBI obtained user information from computers around the world during its two weeks operating as the site administrator for the seized Playpen server. More information is now coming to light, thanks (inadvertently) to a foreign government's inquiries into domestic anti-child porn efforts.