Affiliate Marketing Secrets

I used to work at a convience store years ago and one day about two to three army trucks pulled in. You’ve seen them before, they’re hauling something in back, tied down with a giant green trap. When the soldiers trundled in for refreshments, I tried asking them what was tied down underneath those tarps. I was promptly told that it was top secret like, and that they couldn’t tell me.
“Well,” I said, “where you guys headed anyhow? It’s obvious you’re hauling something somewhere.”
“Can’t tell you that either.”
So I gave up. They paid for their drinks and politely went on their way. My question is, if they were speeding on the highway and got pulled over by a state trooper, would the trooper have a legal right to search the truck? To see what is under the tarp? Would his authority exceed the U.S. governments order that whatever was being hauled was not to be seen by anyone? And if not, how would the soldiers stop him?
I ask all this because how easy it would be for a rich drug lord to buy some of those very same army trucks on the black market, hire some dopes dressed up in soldier uniforms to drive it, and load it up with his illegal drugs and haul it to whatever destination he wanted, if in fact a police officer cannot search one of those vehicles.
Just saying, for people who are on the dark side like that and don’t care about breaking the law, would something like that work? Tell me your thoughts.