Clearly, in Sony's case here it is buy(2), and they've reached into people's accounts and removed content (even using the term "purchased" in the notice email).

This should be criminal. If the sale copy says "buy" "own" "purchase" then they must not be allowed to remove your license to that content by any means.

I'm fine with them removing content from storefronts. I'm even okay with them saying "you're responsible for your downloaded copies, if we decide to discontinue licensing you won't be able to redownload". I'm not fine with them saying "buy" "own" "purchase" and then coming in later "oh we decided to change the licensing situation and so you no longer have access to what you have 'purchased'". That is theft, more than copyright infringement ever could be.