I've had some Irish and English freinds tell me many stories of how to thwart these. Many of youthfull poverty trying to keep the lights on.... Apparently you could jamb all kinds of things in them and it would work - American quarters and other low value foriegn coinage, 1/2" KO slugs, etc. And with a dozen or so kids living in a flat - nobody would fess up after the collector came by, and it would get greased and wouldn't take anything else but real money... I have also heard you could coat a coin in epoxy, and if it stuck in the right place your could crank the knob at will from then on. Other elements of meter theft I have heard about is that sometimes these things would go missing entirely.
