A new lawsuit filed by the ITSERVE Alliance, a trade association for IT technology staffing companies, claims US Citizenship and Immigration Services illegally changed its policy on what types of employers can participate in the STEM OPT training program, Bloomberg BNA reports. The program, which allows international students with science, technology, engineering or math degrees from US colleges and universities to work for up to three years post-graduation, is often used as a launchpad for the H-1B visa. The new policy could block many staffing companies from the H-1B visa program if placing a STEM OPT worker at a third-party worksite counts against them when they later seek the visas.