On Saturday, Sep 6, 2003, at 18:53 US/Eastern, Andrew Suffield wrote:
There is a difference between saying "You may make no further legal restrictions" and saying "You may make no technical restrictions"; it's the difference between "inclusive" and "exclusive", approximately.
The GPL says both. It says you must provide the preferred form for making modifications. A format which uses DRM to prevent or hinder modification, copying, etc. is clearly not that format. (In the source code world, think of obfuscating the source.)
Second, I'm sure you've heard of the DMCA. A technical DRM restriction is a legal one as well, at least in the US. And for anyone who might ever want to step foot inside the US. Or for who the US government doesn't like.
There are, as I see them, real problems with that clause, even if you use the word "and" instead of "or." For example, I couldn't anonymously distribute a document to certain people, using a usenet anonymous remailer and encryption.
I hope the intended effect is along the lines of "if you give someone a readable copy of the document, you must not attempt to stop him from exercising his rights under this license to copy, modify, etc. it" and I think that could be DFSG-free.