After 9/11, US intelligence agencies, led by the NSA, embarked on a massive world-wide surveillance program, monitoring voice, text, email, web, IM, and even video game chat, for signs of terrorist plots. How many billions of dollars did this cost? It seems like they had a blank check.
Given that 9/11 involved smashing commercial jets into buildings, wouldn't you expect that JOB FUCKING ONE on their list of things to monitor would have been the location and status of commercial jets that could be used to attack American targets. And given that the US has military, diplomatic, and commercial interests around the globe, that pretty much means worldwide. It just seems to me THAT would have been top priority, and failure would not have been an option. Monitoring WHERE THE FUCKING KILLER JETS ARE would be top of the list, ahead of thing like monitoring text messages between two 12-year-olds in France or whatever other sleazy shit the NSA/CIA get up to.
So I think that people already know damn well where these planes are. They just don't want us to know that they have the ability know, because that's how intelligence agencies think.