UK experience here....Customs can also check exports before they leave a country. Certainly that was my experience when we used to ship kit from the UK to South America (by way of FedEx).
We'd crate up the equipment then nail down the lid. Then a guy from customs would come out and pull the lid off and rummage around inside checking for contraband and to make sure we weren't shipping things that were on the tech exports naughty list.
We'd crate up the equipment then nail down the lid. Then a guy from customs would come out and pull the lid off and rummage around inside checking for contraband and to make sure we weren't shipping things that were on the tech exports naughty list.