Massive longshot here.
A journalist friend is doing a story on wombling and I said I'd help her.
She'll pay a fee for anyone who speaks to her about this.
Wombling is a bit like extreme couponing, but involves using discarded receipts to top up one's loyalty card (Nectar, Tesco, etc).
People collect receipts out of bins and trolleys, then take them back to the store in question and say "I forgot to bring my card last time, can you add these to my points."
I don't suppose anyone here has ever done this and wishes to admit their shame in a national newspaper.
She says the story won't be critical, but will be a celebration of people's frugality and resourcefulness.