[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

  > We use various non-FSF-copyright C libraries. We don't ship their sources,

To "use" a library has many possible meanings.
Some of them are ok, some would violate our principles or our license.
Could you explain concretely?

Also, who are "we"?

  > We're already working on making it possible to remove from git Emacs Lisp
  > packages that are shipped in source releases:​

Remove what?  From what?