For years, the Department of Homeland Security operated a program allowing tens of thousands of foreign students who recently graduated from a college or university to obtain valuable tech-related jobs. Known as post-completion Optional Practical Training, the program permits former students admitted to the United States on F-1 visas to work in STEM-related jobs for up to three years.

Tech companies love post-completion OPT. They do not have to pay employment taxes on enrollees. They also enjoy significant leverage over these individuals, whose continued residency in the U.S. is conditioned on maintaining their employment status.