> Who could do that? Since transponders are trivial to spoof and interception is a matter of coordination and a radar, you're looking for anyone who has a plan

> Who could do that? Since transponders are trivial to spoof and interception is a matter of coordination and a radar, you're looking for anyone who has a plane that can fly ~500kts at ~35000 feet for a while. So...pretty much anyone who can afford an old Gulfstream 3 or Boeing 707. John Travolta, for example. Nation state not required.