[Right Wing Assault]

Any positive reading would set off alarms monitored simultaneously by Bahamian customs inspectors at Freeport and by U.S. Customs and Border Protection officials working at an anti-terrorism center 800 miles away in northern Virginia. Any alarm would prompt a closer inspection of the cargo, and there are multiple layers of security to prevent tampering, officials said.

So all they have to do is make sure a 'certain' container doesn't go through the device. Who's going to know 800 miles away?

[Beckwith]

So all they have to do is make sure a 'certain' container doesn't go through the device.

Who or what is the "they" you write about?