Barry Salter wrote:

On Tue, 15 Aug 2006 09:33:25 +0100, Courtney Cong
wrote:

(snip)

I only use oyster on the buses - so what happens when my funds run out?

You get a double bleep from the reader when you try to "touch in", and
the driver *should* call you back and ask you to buy a ticket.



As you've already highlighted "should" is the all important word there.
In my experience there are quite a few people who pile on the bus
despite getting their cards getting the rejection double-beep, and many
bus drivers don't do anything about it - in fact it seems to wash right
over them.

I did initially get a bit confused as it seems there are three tones
that the Oyster readers on buses make - the high pitched acceptance
bleep, the lower rejection double bleep, and a special bleep for child
Oyster cards (perhaps also shared with student Oyster cards) - but I
now think some are using an empty Oyster to get past the driver and
evade paying the fare. For some I'd guess this isn't deliberate, but if
bus drivers don't them up on this they won't even know they're doing
it.

Indeed I recently lent a Pre-Pay Oyster card to a visiting friend along
with the explicit instruction that they needed to top it up before use.
They forgot to top it up, predominantly because they'd spent a good
portion of the evening in conversation with Bacchus, but regardless of
this omission they later got on a bus to come back without being
challenged by the driver. Perhaps thats a bad example, given that it
was late maybe the driver couldn't be bothered with the hassle.
Nontheless my observations of this happening at other times suggests it
could be a fairly widespread scam.