There's no indication they were illegal. There's many things you can call it, but illegal may not be part of it.
True, without more info it's possible they weren't illegal, although I can't imagine how. With no warrant, wiretaps aren't legal, nor is any comms monitoring by law enforcement. What crimes could the victims here be suspected of that a judge would sign off on a warrant is the question then - it looks more and more like just one political group wanted intel on another, not that Obama or any in the justice dept or administration were concerned about illegal acts or espionage at that point (ie "the Russians").