Ownership of free-time developed stuff is likely the only thing that has peaked my interest. maybe unions aren't that bad after all. Tho one would hope this type of thing would just be covered by the law without requiring an union to handle, but heh, world is imperfect.
I remember when working in games you couldn't even write blogposts about any type of unrelated to programming thing (e.g. not even about playing guitar) and that was super frustrating. Likely those clauses weren't enforceble but still anoying.