Customs, at least in australia, are no better. They'll open anything they want and have no problem with sealing the package again in a really clumsy way. I've won competitions and had art supplies delivered to me only to find half of them missing because customs took the sealed top off of those tube containers and only put it back on loosely (whereas they were originall sticky taped). I get those things without lids and some of the contents.
Customs REALLY need to be made to take more responsibility for this sort of thing.