Mizter T wrote:

I think the only rule is that you must broadly be going somewhere -
i.e. if you touched in at Ealing Broadway, and are checked on a Met
line train going south from Chesham having not touched-in there then
the ticket inspector might reasonably ask where you were going - if
you say Ealing Common then I'd think you'd be in trouble. In other
words simply touching-in doesn't mean you have the freedom of the
whole network to roam it at will (though if you have a season
Travelcard on Oyster you have the freedom to roam the zones you have
at will). Of course your journey would time-out after two hours as
well, so even if you didn't get checked you'd get 2 x £4 "max cash
fare" 'penalties'.

Hmm - I wonder how the system coped with the closure of Shoreditch when
there may well have been many people travelling to and from the station for
the sheer heck of it.