This is the same Devin Nunes that was accused of bias in the Congressional investigation into the Russian hacking around the Presidential election. As a matter of fact, he is not acting as chairman of the United States House Permanent Select Committee on Intelligence at the moment (although he is still the named chairman) as he is currently under investigation by the Office of Congressional Ethics for disclosing classified information to the public.
Also, lets look at what happened with unmasking towards the end of the Obama administration: Certain individuals around Donald Trump, especially Michael Flynn and a few others with exceptionally close connections to him, were unmasked after the routine capture of communications between Russian officials and US citizens was discovered, communications which helped oust Flynn as National Security Advisor, as well as being central to the current expansion of official investigations into possible illegal collusion between the Trump campaign and the Russian government to influence the 2016 Presidential election.
Putting the above two facts together... until I have some outside, non-partisan source that is backing Nunes, then this looks like a blatantly transparent effort to probably paint the unmasking likely discredit whoever found and revealed the above mentioned conversations, in an effort to paint the entire Russia investigation as illegitimate. And, as a matter of fact, reading a number of sources, it becomes clear that is the EXACT intent of this move. They cover it up by claiming there was 'no justification' because the forms were mostly 'boilerplate'... Yeah, well, at LOT of forms are boilerplate, that's why boilerplate exists in the first place. Just because something is boilerplate doesn't mean that there was no justification. It just means that the justification is used enough that drawing up a standard filler for it is worthwhile. So until there's actual evidence of wrongdoing, Nunes is not exactly an unbiased person in this case, and he has proven before that he is willing to use his biases and act unethically against his political opponents in an effort to retain as much power as possible. If some non-partisan source can confirm what he claims, that's when I'll give these allegations any chance of actually being true, and the actions discussed as being illicit.