This isn't quite the same thing, but it is one of the articles that spurred my thoughts on this subject. In cpython, gc != refcounting. Instagram were talking a

This isn't quite the same thing, but it is one of the articles that spurred my thoughts on this subject. In cpython, gc != refcounting. Instagram were talking about disabling gc, which would have stopped objects which they weren't using from being falsely copied, but wouldn't have stopped objects that they were using (but not mutating) from being copied.