Columbia University tightens security after activist's arrest

Columbia University has increased security measures following the arrest of activist Mahmoud Khalil. Access to the campus is now limited to students, alumni, and registered guests, requiring proof of official business at checkpoints. The Trump administration's immigration policies have raised concerns about potential further arrests on campus. This comes after the administration cut $400 million in funding to Columbia, citing a failure to address antisemitism. Barnard College has also announced heightened security due to concerns about violence. The situation reflects ongoing tensions surrounding student activism and immigration enforcement at educational institutions.