I just heard on the TV that Loretta Lynch signed off on the surveillance. They were emphasizing that as Nunes said, it was likely legal overall, but depending on what the documents end up being:
1) With Lynch signing off, it may in fact not be legal, or would be extremely unethical, or at the very least fishy, given her background.
2) Even if the surveillance itself turns out to be legal, the unmasking would be a violation that should be severely punished, regardless of politics (though civil servant politics appears to be the motivator here).