You want privacy? You want anonymity? NEVER use AIR And ALWAYS pay in CASH!
As Nick Leeson of Barings Bank, Singapore and Singapore PUB Deputy CEO, Choy Hon Tim, discovered, if you are trying to travel incognito, NEVER fly. Nick was scooped up in Germany and Hon-Tim in Malaysia!
Passenger travel data is available as an 'option' on many law enforcement screens - even your local Plod. The better ways to avoid these technical trackers is either have multiple passports or use ground transportation. And book segments separately and switch travel times - as close as practicable to departure.
The US Government is very generous with this technology, giving away free hardware to countries 'of interest' such as drug growing areas, animal part smuggling and terrorists.
Thailand bought their own equipment but Burma (Myanmar) and Kampuchea (Cambodia) had free gifts from the USA so they could even equip their border gates. These 'gifts' often include cameras. The cameras on the borders of Cambodia, as the immigration staffs will tell you, are "connected directly to Washington, USA" - makes the border police think they are a somebody. Even remote border gates, my favourite, have cameras.
But they all have a common weakness. Power and communications. My favourite Cambodian gateway has frequent daily power outages, being at the end of the power line, and if my timing is good I can cross the border bearing electronic goodies from Thailand - with a token 'duty' charge of $100 - because they are out of touch!
Also, remember, C-A-S-H is KING! SITA data includes method of payment with credit card numbers and associated travellers on the same flight. Buy your tickets separately from your friends, and from different travel agents.
Hotel res systems are just as intrusive - there is always hotel space at most destinations - don't book ahead! The FBI even transmits Wanted notices on several hotel networks. Stay at small, cheap, hotels for anonymity!