The song stuff might well fall under work for hire, and surprisingly few artists actually own any rights. Hackers could well fall under that, and I would be stunned if their in house team did not have something like that going on.
As far as hackers. Some do. Occasionally we see things from talks years later, or leaks, or "leaks".
In general hacking terms (and for all that this is its own thing it is still but an aspect of that) the disclosure debate is one that has raged for years. Most do however deem it at least a courtesy to give their hacked device/program/site to the owners of it before sharing it with the world.
At the same time asking for no sharing at all is considered a fairly decent burden to place upon the would be hacker and that tends to spike payments up a bit same as anything else when you ask more of someone. Equally if it gets out that you are going for such things then maybe the next one does not do you a courtesy.