Thread by @KSOSINT

With the change of Twitter policy on "doxing", the banning of accounts like @ElonJet & @ADSBexchange, and Musk's lack of understanding of plane tracking, I will explore in this thread what ADS-B is, how it is used to track aircraft, and why & how this information is public. 1/X

Automatic Dependent Surveillence-Broadcast (ADS-B) is a system that allows for quick, easy, and accurate positioning of aircraft for collision avoidance and air traffic management. As the name suggests the system is automatic and requires little input from the pilot. 2/X

ADS-B out transponders, emit a pulse of information about an aircraft once every second on either 1090 or 978 Mhz. The information includes a plane's unique ICAO hex code, its callsign, speed, altitude, heading, & current GPS cords. Below is an example of raw ADS-B data. 3/X

As of January 1, 2020, all aircraft in the US that operate above 10k ft and near many airports, including major international ones, are required to transmit ADS-B. These and other FAA regs mean that all commercial and 64% of general aviation (GA) traffic do transmit ADS-B. 4/X

The transmitted ADS-B data can be picked up by various sources. Airplanes with ADS-B In can receive data from the other aircraft in their location. Air Traffic Control (ATC) ground stations and even satellites are further used to receive and process this data. 5/X

The data ADS-B transmits on 1090 or 978 Mhz is encoded, but completely unencrypted for universal usage. This allows hobbyists to receive and decode this data using Software Defined Radios (SDR). The video below shows undecoded ADS-B data. 6/X

SDRs can be as inexpensive as $20 and a decent antenna/location can allow for tracking of planes over 100NM away. These SDRs can be turned into full-fledged tracking stations and often this data is fed into aircraft tracking websites such as @flightradar24 or @ADSBexchange 7/X

Websites like these collect ADS-B data from feeders, consolidate it, map it, and disseminate it in near real-time. Depending on the coverage of their feeder networks, websites will have a near-global map of air traffic. 8/X

adsbexchange.com & flightradar24.com

Now that we have looked at what ADS-B is and how it works, I would like to explore privacy with aircraft tracking with ADS-B and some of the claims of the Twitter CEO made relating to whether this information is public or not. 9/X

Currently, the FAA offers two programs to owners of private aircraft two programs that intend to limit the information people have about their aircraft and the ability of people to easily track them: Limiting Aircraft Data Displayed (LADD) & Privacy ICAO Address (PIA). 10/X

The LADD program allows pilots and owners to add their aircraft to a "block" list run by the FAA. This removes info on the aircraft from being sent to the FAA's System Wide Information Management (SWIM) and the distribution of that info by trackers that use SWIM. 11/X

The SWIM program enables users and organizations to subscribe to a data stream of aviation information including things like flight plans. Many flight trackers use this data for their services. Flightradar24 and FlightAware both are known to use SWIM. 12/X

Since LADD is bound only to services that use FAA data, it does little to prevent the tracking of "blocked" aircraft outside of them. For instance, an aircraft registered under LADD will still transmit all the same information over ADS-B as a non-blocked aircraft. 13/X

This means services like ADSBexchange, which does not use FAA data and instead have users submit their own, have no legal responsibility to block aircraft on the FAA's LADD list. For example, ADSBexchange is block-free and has never removed an aircraft from its service. 14/X

The FAA's PIA program on the other hand can make it much harder to track aircraft even on block-free services. If an aircraft owner applies for PIA the FAA will assign a random and temporary ICAO hex code for the aircraft that is not linked to it in FAA records. 15/X

This means that the aircraft it will transmit a different ICAO hex code than would be traditionally associated with the registration. Too make it even harder to associate these temporary hexes, the owner can apply for a new code after 60 days. 16/X

None of this though will nessarily stop a temporary hex from being associated with the actual registration. Multiple methods such as visual confirmation or even analyzing the pattern and places the aircraft travels to can be used to bypass the intended purpose of PIA. 17/X

This is exactly what happened to Elon Musk's jet. After Elon first tried to have @ElonJet taken down and was unsuccessful, he then opted into the PIA program to try to prevent the tracking. Jack Sweeney, the operator of the account, was able to find the new hex quickly. 18/X

This tracking continued even with PIA until Musk's acquisition of Twitter and the banning of @ElonJet and Jacks other multitude of tracking accounts. This went directly against Musk's own promise that he would not ban the account. 19/X

Following this Elon and other prominent figures have shown either a gross misunderstanding on how flight tracking and PIA/LADD works or are intentionally being misleading. As this thread has gone over, ADS-B data is intentionally public facing and unencrypted. 20/X

ADSBExchange, where @ElonJet got its data from, had no obligation to hide the jet because it did not use FAA data. The jet has been available to view on the website the entire time (and still is). All data gathered was above legal and perfectly normal. 21/x

Furthermore, PIA does not block an aircraft or make its info nonpublic. It seems Elon and others confused LADD with PIA, but again LADD is not a universal block on aircraft. Even when using PIA, his jet was still publicly transmitting info, just more convolutedly. 22/x

To conclude. All of this information was entirely public and neither privacy program Elon had his jet opted in to provided the universal coverage he thougy it did. I understand Elon's concerns over privacy especially of his family, but he still remains a public figure. 23/x

@ElonJet is but a symptom of how ADS-B operates and the need for accessible data for aircraft safety. For any of this to change the FAA must either change its policies or how ADS-B works. Elon too can take steps to protect his own privacy in the air. 24/X

For instance Mr. Musk could charter private aircraft instead of using his own. Switching up which aircraft he regularly uses would make it much harder to tell what aircraft he is traveling on at any time. Charter services like these are very common among the ultra wealthy. 25/X

I appreciate everyone who read this far on this very libg thread. I hope that this will help to demystify how aircraft tracking works, the privacy programs work, and their shortcomings. Thank you.

Addendum 1: Here is a map of all active LADD listed aircraft on ADSBexchange as of 17z. As you can see, it is very common. All of these aircraft will not show up on many trackers.

Addendum 2: Here is an example of an aircraft in the PIA program. Note the DCM callsign, which is "DOTCOM" and provided by the FAA PIA aircraft. Also, ADSbexchange has no registration number, as the hex is random and is not linked to the aircraft in any database. ....

This aircraft would be hard to pin down to a specific registration without external means. It could be done, though. For example, a plane spotter could see the registration of the plane on the side of it while spotting. This is the true reg and can be tied back to the temp hex.

Addendum 3: I would like to clearly add that the FCC considers radio broadcasts from planes completely unregulated when it comes to listening, collecting, and disseminating this information. This means ADS-B data is completely PUBLIC and LEGAL for people to share.

Furthermore, Title 47 Section 605 of the U.S. Code clearly carves an exception and protection for the public dissemination of radio communications from aircraft.
justice.gov/archives/jm/cr….
(I am not a lawyer so do not take this as legal advice.)