Recent cases have shined a light on the labyrinthine world of student visas in the US, revealing weaknesses in the system and leading to calls for reform. In January, US agents raided Tri-Valley University in Pleasanton, Calif., and charged it with being a “sham university,” essentially helping foreign nationals illegally obtain student visas in exchange for tuition fees. Tri-Valley, they said, enrolled more than 1,500 foreign students but did not require them to attend classes there. Instead, many allegedly maintained full-time, low-level jobs across the country — in 7-Elevens and Walmarts, for example. The university considered the jobs “career training,” thus enabling the students to work while on student visas. Investigations since the raid have revealed a number of red flags — 533 students were listed as living in a nearby two-bedroom apartment, for example — and yet in 2009 Tri-Valley was approved by the US Department of Homeland Security to enroll international students and thus help them obtain visas. The university, which is not and was not then accredited, reportedly took advantage of loopholes and relatively lax oversight to obtain certification and continue to enroll students. Other cases have exposed further weaknesses in the system. In California, Florida and Georgia, immigration officials have broken up rings that allegedly took proficiency exams and attended and completed classes for Middle Eastern and Korean nationals, for example, to help them obtain and hold onto visas. Cases such as these have raised concerns about the efficacy of the Foreign Student and Exchange Visitor Information System, which was put in place after officials learned one of the Sept. 11 attackers had entered the US on a student visa. Tracking of foreign students once they have arrived in the US is still a “serious chink in the armor” of the system, said Janice Kephart, former counsel to the 9/11 Commission and the national security policy director at the Washington, D.C.-based Center for Immigration Studies. “Vulnerability with universities remains a top issue,” she said. “It’s a clean way to come into the US.” In the wake of the Tri-Valley raid, five US senators in March called for “an immediate crackdown” on the illegal use of student visas, asking the Department of Homeland Security to be more diligent about identifying and conducting site visits at institutions that exhibit particular high-risk factors for fraud and seeking improved information sharing with respect to student visas. At the same time, a US representative has introduced a bill requiring in-person interviews of foreign students every 30 days during the academic year and every 60 days otherwise. It is of course vitally important that we close loopholes in and address any other issues with the student visa system. Ironically, many who are in the US legitimately have already faced difficulty entering or returning to the country (See: Just How Dangerous Are Foreign Researchers?). The challenge before us now is to curb the abuses described here without penalizing those here legitimately who contribute to economic growth — by participating in optics research and development, for example — and in the end help to make us more competitive.