free software: what can constitute a modification?
 

In http://www.linuxquestions.org/questi...g-free-759464/ , I expressed skepticism as to how relevant the fact of free software's being free from intellectual property lawsuits is for everyday non-programmer users, because they can't modify code anyway. Is there any kind of change to an operating system that doesn't involve modifying the code but would still get a user in trouble with a software company if Linux hadn't been free?
For instance, I was thinking of the change in desktop environment that transforms Ubuntu into Kubuntu. If Ubuntu hadn't been free software, would there have been any legal issues in making Kubuntu?

Obviously as long as software patents exist, there remains a danger that all "free" software will be discovered to violate one or another patent. And if that were to happen, end users would be liable as well as authors.

End users aren't blameless just because they're end users. This is why something needs to be done about software patents -- the risk remains that the entire idea of free software expression will go out the window.

Imagine if someone patented certain common words, or mathematical equations, or the idea of a paragraph, or the idea of an idea? Go ahead, laugh, but this is on the same path as software patents -- we only need to walk in the same direction a bit farther.