Tracking has become a bit more prominent in a lot of countries. Nowadays everything is computerized. Everything is shared on both sides. Each country knows the shipper and receiver addresses, and what is reported as being shipped. The amount of stuff that goes in and out is staggering, and they rely on personnel to x-ray each item. Whenever the x-ray inspector picks up something that is suspicious, that item gets pushed off to a different conveyer for closer scrutiny. The same goes for item descriptions. Sometimes an item will get refused just on the description alone and will be rejected even before anybody can open it up.
The customs inspector will open up the package and examine the contents to see it it breaks the rules. Some rules are written clearly, and some can be subject to interpretation. If the item is rejected, the shipper and receiver are tagged and put into a database. If there are multiple hits on either the shipper and receiver address, they could pass this off to the local police for investigation and possibly that all items from the shipper or to the receiver address being tagged as always having to be inspected.
I'm not saying that shipping the item again will get the same results, but it's possible. I had an acquaintance that used to work for Canada Customs. A lot of the stuff she told me was pretty shocking.