We boarded a plane in Miami for Caracas about 5 years ago with 3 large suitcases stuffed full of new clothes and shoes for my Venezuelan nieces and nephews. In customs, my Venezuelan wife was waived through... but not the Gringo. He was taken aside and properly shaken down. All of the US currency that they found (not all that I had hidden, thankfully) was "exchanged for me, as a courtesy" by the Chavista customs agents. In other words, I was forced to exchange (at the official rate of 10 worthless bolivars for 1 US dollar) my currency. This was a bonanza for the customs agents, who knew the black market rate was 300x that.
When I rejoined my wife, all of the checked bags had "disappeared" into thin air. The airline said that all bags were loaded, yet somewhere between the door hatch closing in Miami and the luggage carousel in Caracas... all three bags evaporated into the ether. The customs agents were not interested in hearing my wife's complaints... but there were perfectly willing to arrest us if she didn't shut up and leave.
These military checkpoints along the highways are nothing but places to shakedown the populace of any valuables. There is no valid reason for them to be there... they are constantly letting enchufados (the Chavista "connected" ) pass through with stolen goods every minute of the day and night. Yet they never seem to see entire trucks of "stolen cattle" that pass through every day.