While basically everything about PNRs described here remains unchanged (as it has been since the 60s), government data collection on top of PNRs has become far more extensive since this was written 12 years ago.

If traveling into the US from overseas, you need to disclose a whole bunch of info to get your ESTA, and for the flight itself there's APIS: https://en.wikipedia.org/wiki/Advance_Passenger_Information_...

And for any flight that even overflies the US, there's Secure Flight:

https://en.wikipedia.org/wiki/Secure_Flight

Not all flights. Private aircraft (rich people) and the military follow different rules. These rules target airlines. No airline, no problem.

Not just overflies the US, but gets close to the US. Looking at the airport pairs, flights like Toronto to Europe are deemed to be flying over the US, whether they do or not.

https://upload.wikimedia.org/wikipedia/commons/b/b8/TSA_Secu...