In message , at 22:38:09 on Mon, 8 Sep 2014,
Mizter T remarked:
I haven't seen the T&C for using Contactless cards on TfL (and I bet
neither have 99.99% of the people about to be using it). [...]

The currently available T&Cs for contactless only cover bus travel:
http://www.tfl.gov.uk/cdn/static/cms/documents/contactless-conditions-of-use.pdf

2.2 is especially bizar

"It is your responsibility to check the fare for your journey
before you travel"

Aren't buses flat-fare, and even if they weren't, what mechanisms exist
for you to either enter, or confirm, a fare taken from a contactless
card?

Anyway, 2.5 covers the RPI angle:

"You must be prepared to show your contactless payment card on
every journey you make with it. You must let an authorised
member of staff or a police officer inspect your contactless
payment card at any time during your journey if asked to do so.
You may be asked to touch your card on their portable card
reader as part of their inspection."

Important to remember (on a bus anyway) which card you touched in with!
If you forget on the tube (when it goes live) then there's the whole
'unresolved journey' thing to contend with.

I have a slight issue with the word "inspection", as I don't think the
fact you made a particular contactless payment is stored on the card, so
all they can really do (unless they have a way of downloading the
information from the bus before starting to examine cards) is grab your
data and then charge you a penalty fare or unresolved journey fee later.
--
Roland Perry