Neturei Karta is a political movement. If you define “hareidi” as meaning non-zionist, you end up with many modern orthodox as being hareidi (consider Avraham Burg). If you define “hareidi” based on dress or halachic humras, then you have many fanatic religious zionists in the West Bank who are hareidi.
One could argue that “hareidi” is anyone that the Modern Orthodox consider to be “too frum”.