Re: The Law of Unintended Consequences
"London we have already seen the withdrawal of the ability to pay by cash."
No you haven't. You just have to pay the cash onto an Oyster card ahead of each journey via machine at the station. It's no more hassle than the old inconvenience of using the ticket office or machines, there's barely any more data trail than paying cash. The minimum top up of a fiver is almost the same as a single zone 1 cash fare, but actually buys you two zone one journeys. Since you don't have to register an Oyster card there's no privacy issue (or none that doesn't already exists through CCTV), and the truly paranoid can periodically return their Oyster card and recycle the £3 deposit onto a fresh card to reduce the build up of journey data.