I've seen a lot of stations now posting signs to leave your vehicle at the pumps until fuel is paid for. I agree that it is annoying but it protects the stations from drive offs.
When I travel in the US I'm usually forced to pay inside because the pumps won't accept my credit card without a zip code. I have to go in twice, once to authorize and again to finalize payment. This forces me to stay at the pump and prolongs the process. I do move it when possible before using other services, but I agree, most do not.