This Hoyden About Town post is a great example of why we need better education about copyright and licenses. I'd bet money on the fact that the designer who included both a GPL statement and an all rights reserved copyright statement had no idea if or why those two things are contradictory. Just like the Creative Commons/Flickr/Virgin Mobile case, there are plenty of people who apply these licenses without the least bit of understanding of what it is that they're agreeing to by using them.
Perhaps high school civics classes (Do they still teach those?) ought to start discussing copyright law and licensing issues.