I was very amused to realise that it was actually cheaper for me to buy a RFID ticket, run it into the debt limit of $1 and then dispose of it at the end of the

I was very amused to realise that it was actually cheaper for me to buy a RFID ticket, run it into the debt limit of $1 and then dispose of it at the end of the trip. Talking to the station staff about it they acknowledged that they didn't like it but that it was perfectly within the law to continue doing so because after all it was still a valid ticket. There's probably room for doing a mix network in places where this loophole isn't possible though, even just a scheme when you see another person adding funds to a zero balance card and it becoming custom to swap your empty one for theirs would do the trick for privacy.