Mahmoud Khalil, an anti-Israel activist who led protests on Columbia University's campus, has been arrested by ICE agents. Khalil was taken into custody at his university-owned apartment on the Upper West Side of New York City. ICE agents claimed they were acting on a State Department order to revoke his green card and student visa, although Khalil's attorney argues that he is a legal permanent resident. The arrest comes after President Trump threatened to deport foreign students involved in 'illegal protests' on campus.