That may be because the evidence against her is flimsy, or because it is too bad (or too secret) to present in court.

ECONOMIST: Russian espionage

They negotiate in secret and then emerge to announce their agreement and present it.

CENTERFORSECURITYPOLICY: Center For Security Policy

The decision to form an electoral alliance was reportedly the result of secret negotiations between Mr Netanyahu and Mr Lieberman without senior officials present.

BBC: Israel's Likud Party and Yisrael Beitenu to join forces

"Some activities of American prisoners of war within German prison camps must remain secret not only for the duration of the war against the present enemies of the United States but in peace-time as well, " the document says.

CNN: Lawmakers to Army chief: Honor soldiers held as slaves by Nazis