@jhulten @thomasfuchs @deco @drwho I believe they would argue that they are covered in this regard by 4 (technical modifications allowed) and 5c (no downstream restrictions). They retain the same rights (incl. modification) to the content once created as any individual who they distribute the content to under CC-BY-SA. (see also their ToS section 6).
Not defending them (I think this is morally shit, but probably legally allowed), just saying I don't think that's a valid avenue to fight them in.