Here’s an easy way to remove your personal information contained in media files purchased from iTunes.
I use a great little application called iTMS Scrubber for this purpose. It’s available for both Windows and Mac.
Instructions for the Windows version:
Simply extract the contents to a folder, copy in the album files you want to de-personalise (don’t use your originals!) and run itms-scrubber. It will also extract the album art to a folder.jpg.
Instructions for the Mac version:
Simply drop your music and/or music video files onto the icon. It will process them in-place and write out report files to show the tags before and after scrubbing. You must drop the actual audio/video files, not the folder containing them.