Opened letters (Munich)

Have any of you received letters from abroad that were already opened on arrival? We received a bithday card today from home today in an envelope that was so blatantly slit open. I really could not believe it. Not a stamp or note that indicated customs had taken a look. I have had packages held up before but they always came with a stamp of inspection by customs. But a letter or card? We make such a fuss here in DE abt the NSA and Deutsche Post allows this to happen? I Have read stories about theft going on at the Post but I didnt think it was this bad until today. advice ? Your experiences?