If there is resentment against the ATs -- and that is just about a certainty -- there will be cases of resentful attendants shorting the fuel delivery, or even sabotaging trucks (water/sugar in the tank).
So, maybe the trucking companies hire min-wage attendants to work the pumps at designated stations along the routes. The stations that permit AT refueling would be obvious targets for Luddite retaliation.
Actually, the ATs themselves would be pretty obvious targets for vandalism. They would be easy to identify -- driving at 45mph in platoons, as described in the article -- and unprotected along the vast open stretches of US interstate highways. I would expect many, many ATs would arrive at their destinations with rifle bullet holes in them.
I don't think protecting trucks from terrorists is a major issue - providing security is just a minor added cost, as is armoring the trucks.
The real issue is that for the most part governments seem to be siding with the terrorists rather than shutting them down.