Norwegian municipality loses 25 000 classified documents in the mail (nrk.no)

English summary: When Rana municipality changed archive system they choose to send 300 000 documents, of with 25 000 was classified, on an usb stick trough snail mail. When the envelope arrived it was torn, and the usb stick was missing. The Rana City manager warns any finders that it is a criminal offense to misuse data one does not have legal access to.

Since that does not state that the data was encrypted we can probably assume that it was not.