> That said, "US selectors" shouldn't return the results that they do in the first place.
Determining if a "selector" is tied to a U.S. person is actually a very subtle and very hard problem.
Let's take a phone number +1 (212) 555-1234
Is this a US selector? It's a selector for a phone in the US, but that's not the same thing as a phone number tied to a US citizen. Let's say I'm following a senior North African pirate with a Maltese mobile +356 2010-1234 and he calls/is called by my number above?
- Should I follow it? Or is it absolutely off limits for me because it happens to be a U.S. number?
- How do I determine if it's tied to a U.S. person?
- What if it's a shared number between a group of associates, all of whom are not U.S. persons except for one?
- Is that number off limits now?
- If it is a U.S. person what should I do with it?
- Pretend it doesn't exist? Turn it over to U.S. Federal law enforcement? Who should I turn it over to? DEA? FBI? ATF? DHS? The Coast Guard? U.S. Customs and Border Patrol?
It's actually a significant intelligence task to figure this out.