I'm not sure I follow you. How is not reporting something that has already taken place something that would cause fear. The deaths already happened. It isn't that they are not reporting a warning if they know a bomb is there and tell people to back away. I don't see lack of reporting induces fear. Ignorance isn't bliss? We seemed awfully blase as a nation for decades when the problem was just something "over there."
And I don't think it was a government induced requirement they were talking about just a way for the newspapers on their own to quit feeding the need for the publicity the terrorists seek. The discussion I heard never mentioned government once.