A leading Pakistani politician and campaigner against U.S. drone attacks was detained and questioned over his political views on Friday while trying to enter the United States. Imran Khan says he was taken off of a flight from Toronto to New York City and interrogated by U.S. agents about his public opposition to drones. Announcing the episode after his questioning, Khan tweeted: “My stance is known. Drone attacks must stop.” Earlier this month, Khan led a march of thousands of people in Pakistan to rally against the drones.