On unmasking:
U.S. persons are redacted in signals intelligence reports of conversations with foreign nationals under surveillance.
Unmasking is making the identities of those U.S. persons known so that the reader can better understand the context of the conversation.
The crime (so far in the story as it's playing out in the news) is not in the unmasking per se but in the leaking of Flynn's name and the conversation with the Russian ambassador to the press.
There are also questions as to why someone like Biden or Power or the Treasury Sec. needed to know the identity at all.
Which leads to this >>9210662