One of the great perks of flying privately is right there in the name: privacy. But the ability to stay away from prying eyes only applies inside the cabin. Social media accounts that broadcast flight patterns of noteworthy names—including Tom Cruise, Kim Kardashian and LVMH chairman Bernauld Arnault, as well as numerous sanctioned Russian oligarchs—have racked up millions of followers combined, with the Twitter handle @elonjet gaining national attention after Musk himself suspended the account. The spotlight it shines is equal parts geeky hobby, gawker-level curiosity and data-driven emissions-shaming—and Arnault, at least, eventually got sick of the glare, selling his Bombardier Global last fall and switching to charter flights with private passenger manifests.

“It’s akin to driving on the interstate and having anybody pick up your license plate to see who’s in the car and where you’re going,” says Doug Carr, senior vice president of safety, security, sustainability and international affairs for the National Business Aviation Association (NBAA). “This isn’t just about lifestyles of the rich and famous. It’s about basic security and not being able to track people in real time—which, by the way, is illegal anywhere else.”

LVMH CEO Bernard Arnault on board his private jet between Beijing and Shanghai in 2004.
LVMH CEO Bernard Arnault on board his private jet between Beijing and Shanghai in 2004. Marc Deville/Getty

The issue came into focus a decade ago, when a restaurant-supply firm CEO, who used aircraft to conduct business, was cyber-stalked and tracked by competitors. Then there were the wounded veterans who were followed and met by anti-war protestors at their home airports. Martha King, who runs pilot-training academy King Schools with her husband, John, had several unstable “fans” harassing her from out of state. One showed up unannounced and threatened her. “Privacy sounds abstract, but it got personal for us quickly,” says King. “Now, we’re more cautious flying into unknown airports.”

The FAA moved to fix that loophole by creating a way to temporarily disguise a jet’s tail number through the Privacy International Civil Aviation Organization Address Program (PIA). But joining the program is significantly more complicated than signing up for LADD, requiring physical modifications to the transponder and temporary call-signs—and when it comes to the latter, “you’d likely need to change that code on a routine basis,” says Heidi Williams, NBAA’s director of air traffic services. Besides, the new codes are not recognized outside of US airspace.

As we’ve seen from broader celebrity culture, if there’s enough public interest, the trackers will find a way—the FAA can’t stop enthusiasts or paparazzi from physically watching jet traffic at a local airport and then sharing those tail numbers, for example. Spokesperson Tammy L. Jones says the agency is expanding PIA for US-registered aircraft to include FAA-managed international airspace, but that no mechanism currently exists to encrypt secondary surveillance and communication technology, and that modifying the next ADS-B generation could be a decade away.

Meanwhile, the NBAA is in talks with trade associations in Canada and the European Union, which account for 40 percent of global business-aviation activity, to create an international PIA-type program. But universal adoption would require “a conversation in every part of the globe on what this program means, and how it would interface with air-traffic-control systems,” says Carr. All of which leaves pilots like John King, whose wife was physically endangered, frustrated, angry and wondering: “Why should we have to give up our privacy whenever we get on an airplane?”