Disagree.
Blackmail and hostage taking are causing harm to others for your own benefit.
Telling a company, “Hey, I found this vulnerability in your software; I’m not going to tell anyone until you’ve had a chance to fix it” is, if anything, minimizing benefit to yourself for the benefit of others. After all, a viable attack vector is more valuable than an obsolete one. A better example of blackmailing/hostage taking , in my opinion, would be the case of Ashley Madison. The hackers tried to leverage the ill-gotten information for something that was of benefit to them, and when they didn’t get it, they released the information, hurting many other people.
This is not like Ashley Madison. Yes, the airline industry has been harmed by this, but only because they were relying too much on security through obscurity in the first place.
