Ian Grant
Subscriber
Yep - and this is the elephant in the room that nobody ever seems to address.
Most overseas mail is checked with exactly the same type of scanners used in airports for carry on baggage. Anything suspect may then go through a more severe scanning process. This is actually what happens with hold baggage as well.
These scanners are used in far more places than some people realize. It's not just when flying, ports, cruise ships, shopping centres, courts etc all use them.
In Peru they scan your baggage when you pass through Customs & Immigration going into the country.
Ian