The National Security Entry-Exit Registration System (NSEERS) was a U.S. immigration program established after the September 11 attacks to monitor non-citizens from specific countries deemed to pose a national security risk. It required individuals from designated countries to register with the government, undergo fingerprinting, and participate in periodic check-ins, leading to increased scrutiny of Arab and Muslim communities. This program significantly impacted perceptions of immigrants and fueled Islamophobia in post-9/11 America.