I thought it'd be fun to set up a 1 mile DMZ at the US southern border, with 50cal machine guns, tripodded and pointing south, every 100 feet.

Then, you can advertise the location as a "Patriotic Vacation Spot" where: "YOU Can Do YOUR Part In Keeping America Safe!"

And let US Citizens walk up and take a few shots to the south. You know... To keep them at bay and remind them there's a legal process to come into our country and THAT AIN'T IT.