Saw a nice program from germany yesterday, Computer Club, where they demo'ed how to defeat one of the various schemes - garbled data track outside the music track(s). On the demo disc (can't remember what it was) this track was rather obvious.

The quick way was to attach a piece of non-transparent tape or a piece from a Post-It note tangentially on the outside of the CD, covering part of the data track (a segment of the circle). For more secure (less imbalance and no risk of it going astray inside the drive) or more permanent, yet removable, application, a water soluble black marker was recommended.

Article (in german) here. babelfish translation is so-so...

They also noted that in a few months they might not have been able to discuss this, as germany is considering new laws...

/Michael