David F wrote in uk.transport.london on 25 May 2007 02:34:49 -0700
ps.com:

On 25 May, 06:37, David of Broadway
wrote:
ISTM that the only safe way to handle this is to assume that everybody
who didn't touch out (during the time this was in effect) exited at
Sloane Square and to charge accordingly.

Hypothetical, but how about some sort of long-range scanner? So
everyone passing out the door would effectively get touched-out...

I carry my Oystercard in my wallet all the time, but on those
occasions when I'm using National Rail I'll buy a card ODTC, so I'd
rather object to having my journey counted on an Oystercard I happen
to have about my person.

ISTR some previous discussion here about the range of the cards being
limited following experience during testing?

Dave