Yes, Mark Pilgrim had an interesting blog post about that:
Recently, someone did the unthinkable: they published their own version of Dive Into Python and got it listed on Amazon.com. This apparently caused a small firestorm within Apress, the exact details of which I am not privy to, but which (I am told) became a somewhat larger firestorm after the Apress executives realized they had no legal recourse, and asked my opinion on the matter. You see, the book is published under the GNU Free Documentation License, which explicitly gives anyone and everyone the right to publish it themselves. (I was about to write “gives third parties the right,” until I realized that there are no third parties because there are no second parties. That’s kind of the point.)
Recently, someone did the unthinkable: they published their own version of Dive Into Python and got it listed on Amazon.com. This apparently caused a small firestorm within Apress, the exact details of which I am not privy to, but which (I am told) became a somewhat larger firestorm after the Apress executives realized they had no legal recourse, and asked my opinion on the matter. You see, the book is published under the GNU Free Documentation License, which explicitly gives anyone and everyone the right to publish it themselves. (I was about to write “gives third parties the right,” until I realized that there are no third parties because there are no second parties. That’s kind of the point.)
http://diveintomark.org/archives/2009/10/19/the-point