"The FAA has a Block Aircraft Registration Request (BARR), so a celebrity, politician or high-profile person can request their aircraft to be added to the BARR list, meaning that their flight information is not made public. The speakers Dustin Hoffman and Semon Rezchikov demonstrated “a serious, unpatchable method for tracking otherwise ‘untrackable’ BARRed aircraft” and showed how you can bust BARR too by monitoring LiveATC.net and downloading ATC communications. After developing a speech recognition (speech-to-text) software, the researchers were able to scrape radio transmissions of BARR flights that are arriving. OpenBARR currently tracks flights arriving or departing from Las Vegas airports: Henderson, McCarren International, and North Las Vegas, but the researchers plan to include other cities soon.
As you might imagine, finding a way around the BARR list has upset some superstars who didn’t want to be tracked. NBAA spokesman Dan Hubbard blasted away at the researchers, “Getting on an airplane shouldn’t amount to forfeiting your security and privacy to anyone, anywhere in the world with an Internet connection.” Perhaps he had not heard of the flight tracking apps that forfeit the "security and privacy" of regular folks on regular flights?"
computerworld.com/article/2472455/curious-hackers-inject-ghost-airplanes-into-radar–track-celebrities–flights.html