Last week, I travelled every day from Kings Cross Thameslink to
Bedford on 'City Fliers' in the morning and returned back to London
with Midland Mainline, on a weekly First Class season.

I noticed that on none of the five occasions I travelled with
Thameslink for over an hour in the am (ok, after the peak) there was
no conductor/RPI on board to check tickets. Is this usual or unusual?
I know Thameslink services are Driver Only Operated but I'd have
thought there would be some sort of revenue protection on board. Then
again, major stations on the City Flier route such as St Albans, Luton
Aiport, Luton and Bedford all have ticket barriers so I guess
fraudsters can be 'caught out' but I found it unusual nonetheless that
I saw no revenue protection staff on board any of my journeys, as I
noticed a few Standard passenger sat in First Class and on board staff
would act as a deterrent. The same has applied in the past to WAGN
services from Kings Cross to Peterborough where I've never noticed an
RPI on board.