Seeing as the OP framed the question in terms of moral responsibility: Anyone who has not agreed to keep the leaked information secret has absolutely no moral duty to not discuss the leaked information. Anyone who has agreed to keep the leaked information secret has a moral duty to see through their agreement (unless a greater moral duty comes along of course).
I think you mean legal responsibility here, and the agreement would be an NDA of some sort.
The morality, whether good or bad, of spreading the information those people have leaked is a topic that is debatable and open to interpretation.
No, I definitely meant moral responsibility.
If Alice and Bob agree to keep a certain piece of news secret from the world, and Eve discovers said news, Eve has no moral responsibility to also keep it secret. In fact, it could be argued that if anyone is acting immoral, it is Alice if she then tries to smear Eve's reputation merely for discussing news that Alice would rather not be public.
So, if my wife had cancer and we were trying to keep it under wraps and a buddy of mine, Fred, found out somehow and blabbed to everyone under the sun, I would be wrong to be angry at Fred? I would be in the wrong for trying to keep the cancer a secret? Insanity. Fred is wrong in this situation.