Reading protected PDF files on the Amazon Kindle 2

I recently bought a new Nikon DSLR on Amazon.fr as it had the best price I could find in Europe. As usual it arrived in no time in perfect condition but it only had the French manual. I found an English version of the  PDF version of the Users' Manual on the Nikon web site but is not readable by the Amazon Kindle 2 as printing is password protected.

I already own a paper copy of the manual so I don't feel guilty about removing the password protection of the PDF file so I can read it on my Kindle. This one line command on Mac/Linux uses GhostScript to remove the password protection:

gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=unprotected.pdf -c .setpdfwrite -f protected.pdf

It also reduced the size of the file from 23Mb to 14Mb :-)