A really odd thing happened while driving yesterday: in the middle of one track playing, the empeg suddenly played a few seconds from a totally different track. (...) The few seconds were from the German national anthem.

Heh, they got you.

There are people who do this on purpose: Deliberately upload a messed-up track into the file-sharing network with the intent of pissing off the pirates.

This is not a software bug or a sharing-service problem, it's the work of a vigilante. Slashing the "Z" into the front of your shirt is the "do-it-yourself" part of the task, though.