Electronic barrier at garages?

[Grandad Gaz]

I have noticed a couple of warning signs on fuel pumps saying that failure to pay for fuel will result in an electronic barrier stopping you leaving.

There are no signs of anything which would stop you leaving the local Shell garage where these signs are!

Anyone else seen them?

[Toaster Pilot]

Maybe they'll install these http://www.youtube.com/watch?v=O0wY-hvMC44&fea...

[Eighteeteewhy]