actually I wonder if it might not be more of a safeguard to ensure
that those who have access to an Oyster card's journey history really
are the bona fide holder of said card. Something to scratch my head
over...

That was always my assumption and I think it was discussed in this group
some time ago. It makes it that bit more difficult for a spouse/partner
to establish that the card user was not in the office all evening, went
away on Saturday when the team were playing at home, was .....
--
Robin
PM may be sent to rbw0{at}hotmail{dot}com