I wrote these to see if some mp3's I bought online contained any personally identifiable information. Surprise, they did! Specifically, there was info I didn't want to keep in the COMM (comment) field, as well as 3 custom fields named TXXX, TXX01, TXX02. Oh, and an attached picture (APIC) that I didn't really need, and a GEOB field (which can contain ANYTHING, but the MIME header in it indicated it was ALSO a picture).
So, if you run 'list_tags.pl' in the directory with your mp3's, it will give you some nice spew you can visually inspect to see what tags you might not want to keep. 'wipe_tags.pl' will remove the fields I just mentioned, so edit to taste.
Note: I'm not condoning you sharing purchased, copyrighted works. My perfectly legitimate motivation for throwing these scripts together is that I don't want to be blamed for distributing copyrighted works illegally if someone were to steal my files. In *theory*, I can imagine a non-tech-literate judge or jury saying "That's your download ID from the mp3 retailer, we found it somewhere else, case closed" -- and it would be very hard to prove that I did not intentionally distribute the material. Copyright has gone from an idea meant to benefit both authors AND the public to a system to protect only the author's rights. Here endeth the rant.
Another Note: This was originally picked up by Ben @ arsgeek.com. Thanks, Ben!