Good article, I wonder if the solution is something akin the Amazon store.... you just hop in, and perhaps tag you card, either in the station, or inside the

Good article, I wonder if the solution is something akin the Amazon store.... you just hop in, and perhaps tag you card, either in the station, or inside the train/bus, which contains some kind of (one way) hash of your face.... The card buying process can be anonymous, and the hash is a card/face combination, (i.e. you can't repro the hash, unless you have both). The card is only needed for tourist/people that want privacy. For the rest, you can just create an account, and have money deducted automatically when you step in a train. No tagging necessary. This requires: 1. Great face recognition. 2. Strict privacy rules 3. People being ok with it