Happened to me at Ohare in May. They stopped the whole line for 10 minutes when they set it up.
They brought out portable, battery operated Milwaukee tools fans and a sniffing dog. They made people walk 2 at a time, through a glass walled walkway for about 50 ft and a tsa guy walked a dog behind you. Once you go through the tsa ID check the told us to leave shoes on and electronics in our bags. They still sent the bags through the X-ray though.
My brother in law flew out of St. Louis and described the exact same thing a week later. Weird.
I have no idea if this is correct. But imagine if you have a setup like Apple’s AirTag. Except when you receive a signal (message) you also relay it to whoever’s path you cross for the next X amount of time. The more people using the app the bigger the mesh network gets.