Well the usual Wizards of Smart® are saying the unmasking was not illegal.
But some are admitting that it was illegal to disseminat the intelligence, with the unmasked, identities.
And so, of course, was the final step in the Obama administration's scheme:
Leaking the unmasked/disseminated documents to the MSM.
There were probably at least a few cut-outs along this line connecting Susan Rice and the MSM (such that Rice could claim plausible deniability of knowledge of persons taking the clearly criminal steps).
[. . .the unmasking was not illegal.]
On the face of it the “unmasking” may not have been illegal but when done repeatedly in a pattern suggesting the White House used the NSA apparatus to eavesdrop on domestic political opponents to affect a U.S. election it then could become a criminal conspiracy.