In most cases it would just be added like all other code as if it was proper/allowed until someone brought a civil suit with enough evidence to claim they had n

In most cases it would just be added like all other code as if it was proper/allowed until someone brought a civil suit with enough evidence to claim they had no permission to use the code AND it somehow damaged them, which could be quite difficult and prohibitively expensive. So I would argue in most cases people will get away with it. We must remember that the only person's opinion that matters on what's actually illegal or not is a judge's.