some may want to consider locking fuel caps and "losing their keys" until they (give them directions) go down to the court house and get search warrant. another thing to consider is to install filter screens inline with the filler neck and make them aware that theres a filter screen to prevent trash from entering your 11 thousand dollar fuel system- considering dealer cost for injectors, transfer lines, fuel rail+lines+pressure relief valve, injector pump, fuel filter housing, electric fuel pump (more if aftermarket)+ fuel lines, and tank. make them aware knock out my screen and I will be knocking on your supervisors office door with a bill to drop tank, remove and replace damaged screen and fuel system cleaning plus tow from where he stopped me to where i got repaired.
if enough people do it enough the department may not bother with those that refuse. wont be worth the hassle.
then again if you want to run the fuel and get away with it add a 2nd filler neck to the truck (such as under toolbox accessed from in toolbox) then re route your hoses to the new filler neck and go ahead and run the old filler neck to a small race fuel cell from jegs filled with taxable diesel.
if theres a will theres a way