Is the watermark different for each user in our iPool?
It is even better: The watermark is different for each download. Each single download is logged together with the user name, a time stamp, the artist name and title as well as a unique download number. This unique download number is embedded as a watermark into the audio signal of each downloaded MP3 file. If you find one of your music titles in a sharing network, simply read out the unique download number from the MP3 file and have a look at your download log to trace back the originator.
