Here's a case of marketing gone terribly wrong: McDonald's Japan ran a contest giving away mp3 players, and gave away a little extra with each one:
However the MP3 players were infected with QQpass a very dangerous malware. So your PC is infected once you connect the DAP and it starts logging and transmitting username, passwords and other vital information. McDonalds Japan has apologized and set up a 24 hour helpline for those affected by the spyware loaded MP3 player.
I added "DRM" to the tags because this smells like a music industry sponsored piece of stupidity. In general, you should be the only one with indigestion after eating at McDonald's - your PC shouldn't feel your pain.