Observation: China, a few years back. The train system has been going from a paper ticket approach to a ID-based approach. (You've had to show ID to buy the

Observation: China, a few years back. The train system has been going from a paper ticket approach to a ID-based approach. (You've had to show ID to buy the paper tickets anyway.) They also work on a system where you scan your ticket upon leaving, also--it catches someone who rides further than they paid for. At the time some cities were fully converted and were willing to accept (with some difficulty, the scanners were picky!) our passports others only had the local ID readers. (The local ID has embedded RFID, you just touch it to the scanner plate and the gate opens.) However, others were not--a couple of times security simply let us out without doing any sort of check.