There have been reports (and I can tell it from my own experience on the Wroclaw airport) that personnel on most Polish airports regularly steal stuff from traveler's suitcases.
Alas, it's not just Poland.
Thiefrow is well named, for instance.
Travelers taking a flight from Poland to other continents (like America, Africa, or Australia) are most vulnerable to the fraud.
There's also no guarantee that it's not Customs doing this, and not necessarily in Poland.
They target electronic equipment, computer parts, video cameras, laptops, etc. They just open suitcases and take what they want. They know the traveler is much less likely to get help / complain from another continent. When they stole my new hard disk and an old video camera, I learned my lesson. But it happened again to TWO of my friends who also took a flight from the Wroclaw airport, through Warsaw, and to the US.
How do you know that it was the Poles and not somewhere else?
Then again - who puts that kind of stuff in their checked in luggage anyway?