In Brazil, journalist have the constutional right to protect their sources. In the US it seems it was a gentlemans agreement that now got broken.
I think it was a constitutional agreement that got broken. Because the constitution is a law, laws are ruled on by the courts and enforced by the executive, and both the courts and the executive have decided that laws don't apply to them. There's long been the wry observation that people with unlimited dollars for lawyers experience a different set of laws than the rest of us, but the United States now is a lawless country that is coasting on the longstanding precedent that most laws apply to most people.