In message , at 22:38:02 on
Mon, 4 Mar 2013, Richard remarked:

I can't believe that retrospectively fining people because the gripper says
that you were on the train but your bank account details don't show that you
have paid, is going to stand up to expert court scrutiny.

Well, it's not really a fine. It's a charge for not being able to
demonstrate that you've done the right thing

The Paywave terminals[1] don't give receipts, so it's quite difficult to
demonstrate [2] that you've used the card. The objection is to in effect
allowing your card to be used to collect a PF off all cardholders, which
they'll nullify if it turns out later that you have paid.

[1] eg on the gates into the tube.
[2] To a gripper on the tube system, who probably won't have his own
wireless connection back to the bank.
--
Roland Perry

On Tue, 5 Mar 2013 09:42:04 +0000, Roland Perry
wrote:

In message , at 22:38:02 on
Mon, 4 Mar 2013, Richard remarked:

Well, it's not really a fine. It's a charge for not being able to
demonstrate that you've done the right thing

The Paywave terminals[1] don't give receipts, so it's quite difficult to
demonstrate [2] that you've used the card.

Yes, to be clearer I meant demonstrate *somehow*, but I agree that
there is a difference that I hadn't thought about: the Oyster knows it
has been validated, the bank card doesn't, but I don't think it really
matters -- if you have seen the green light and read the message, the
chances of you later being found not to have paid are almost zero.
False positives are going to be in the user's head, did it register my
card? I think this sort of problem is easier to imagine at a station
gateline than on a bus.

Richard.