As Putin faced the biggest threat to his 23-year-reign, two presidential planes reportedly took off from Moscow before switching off their transponders en route to the Tver region, where he has a residence.

Source: https://www.dailymail.co.uk/news/live/article-12231383/Wagner-Group-LIVE-spy-agencies-briefed-President-Biden-Prigozhins-mutiny-days-ago.html?ns_mchannel=rss&ns_campaign=1490&ito=1490

Commercial ships are required under international law to keep their identification transponders switched on to prevent collisions and help authorities fight maritime crimes.

Source: https://gcaptain.com/u-s-revives-cold-war-submarine-spy-program-to-counter-china/

For years, ships determined to cowl their whereabouts have resorted to turning off the transponders all monumental vessels use to signal their location.

Source: https://www.mccourier.com/fake-signals-and-american-insurance-how-a-dark-fleet-moves-russian-oil/

Motorists without switchable transponders can get one at to save an average of 40% off license plate tolls.

Source: https://www.realvail.com/17777-2/a17777/

“So far, around 900 transponders have been fixed on boats in Chennai, Cuddalore, Nagapattinam, Thoothukudi and Colachel.

Source: https://www.thehindu.com/news/cities/chennai/600-fishing-boats-in-chennai-fitted-with-transponders-with-isro-technology/article66983311.ece