The reason why is important. There’s too much information out there for most people to pay attention to, let alone figure out whether they believe it or not. Hence, most people rely on other institutions such as media organizations to tell them which information is worth caring about. Not only do people not pay much attention to information until it gets the stamp of approval from some authoritative institution, but this information is transformed, because everybody knows that everybody else is paying attention to it. It stops being mere information, and becomes knowledge — generally accepted facts that people use to build their understanding of what everybody knows about politics.
Established newspapers like the New York Times, The Washington Post and the Financial Times play a crucial sociological role in deciding which information is important and trustworthy, and which is not. When one of these newspapers publishes information, it is legitimated as knowledge — which people are not only more likely to take seriously themselves, but may have to take seriously, because they know that other people are taking it seriously. European Union governments knew perfectly well that the U.S. had been tapping communications in their building (and if you read specialist sources, you knew about this, too). However, these governments found it more politically convenient to ignore U.S. spying than to make a big fuss. When this information became knowledge — when it was published and treated as authoritative by major newspapers — it became impossible to ignore any longer.