On 10/10/2014 15:11, Neil Williams wrote:

On 2014-10-10 13:45:06 +0000, Mizter T said:

Scenario 2: I paid with my contactless Visa/Mastercard credit/debit
card, but how are the rest of my family going to travel around London?

I still think the "free ticket against a universal tourist tax" approach
practiced elsewhere, e.g. throughout Switzerland, would be an excellent
idea and would catch much of this.

Including those visiting friends in London for the weekend, for example?
Or the day? (Not everyone arrives in London by rail with the possibility
of having bought an outboundary Travelcard - they're not available for
journeys from further afield anyway.)

Sorry, there are simply far too many exceptions to your neat categories!