Click here for a video that explains unmasking standards for Foreign Intelligence Purposes. To be legal, unmasking standards are supposed to be for Foreign Intelligence Purposes (and not for partisan politics). However, specific unmasking standards are highly classified and can never be released to the public or to the media. Supposedly.
Classified, huh? This means that it is not possible to tell from the outside when national security official's unmasking is not legitimate. Thus, all allegations that Susan Rice did anything wrong are baseless, as well as irresponsible. In other words: FAKE NEWS!!!111 Based on common sense alone, when the intercept of a foreign actor's communication involves a U. S. person who is a notable player, it's rather hard to analyze this intelligence without knowing the player's identity; from the moment Trump became a viable nominee, persons close to his campaign are by definition notable players. Presumably then, unmasking them would serve legit Foreign (counter)Intelligence Purposes.