The cogent documentary, “Surveilled,” now available on HBO, tracks journalist Ronan Farrow as he investigates the proliferation and implementation of spyware, specifically, Pegasus, which was created by the Israeli company NSO Group. Directors Matthew O’Neill and Perri Peltz follow Farrow as he meets with individuals including a former NSO employee, who spoke on condition of anonymity; Ron Deibert, of Toronto’s …