Well, such testing groups do exist for both door locks and cyber security. The idea is that a company, to make sure that its safety measures are indeed up to snuff, will have such a group try to gain forcible access. If they fail or only succeed after a ludicrous amount of effort - ie, more than the average hacker would ever bother with - then its a pass. If they get in far too easily things need to be improved.
In this case though, Sony obviously did not ask for this group's services, so this leaning way closer to a protection racket.