Another perspective:
http://www.slate.com/articles/news_and_politics/politics/2017/04/i_hope_susan_rice_was_keeping_tabs_on_trump_s_russia_ties.html
In fact, it would have been a dereliction of duty for the Obama administration, which was still in charge of the country’s national security, to ignore suspicious contacts by members of the Trump transition team. After all, at the time, the FBI investigation into ties between the Trump campaign and Russian attempts to subvert the election had already begun. We also now know that Michael Flynn, who would soon assume Rice’s job, was a paid foreign agent of Turkey. According to ex-CIA Director James Woolsey, Flynn met with representatives of the Turkish government to discuss kidnapping Fethullah Gülen, a government critic who lives in Pennsylvania, and sending him back to Turkey outside of normal extradition channels. (Flynn denies that this happened.) Trump himself has alleged financial ties with Russian mobsters. At the time of the alleged unmasking, all these men were still private citizens. If they were talking to targets of American surveillance, the people in charge of our national security had an obligation to understand why.
Obviously, when American citizens get caught up in incidental surveillance, it raises civil liberties concerns. If Trump and his apologists wanted to argue that this incident shows the need for greater privacy protections for all Americans, they might have a point. Instead, they’re trying to pretend that the fact that they were monitored on perfectly legal surveillance is evidence of a sinister plot again them.