The problem is that it is argued that Kazaa actually intended for its network to be used for distributing copyrighted material online; to maximize its advertisment revenue, etc
"Articles, which are often heavily opinionated, almost never carry a byline. This means that no specific person or persons can be named as the author. Not even the name of the editor (currently Bill Emmott) is printed in the issue. The author of a piece is named in certain circumstances: when notable persons are invited to contribute opinion pieces; when Economist writers compile surveys; and to highlight a potential conflict of interest over a book review. The names of Economist editors and correspondents can be located, however, via the staff pages of the website."
Slashdot Mirror
Compare that with the Creative muvo n200 1gb version for £109 on amazon.co.uk .
Based on creative's pricing, I would pay £140 for the NW-E507. Anything more than that would not seem like a reasonable purchase.
Read the 'If Kazaa can block traders of child porn, it can block copyright infringers too article on The Register.
I also found the article at The Times to be more informative than the one linked one on /.
You can apply what is known as a Software Restriction Policy and enforce it strictly so that only approved software is installed on system computers