The U.S. administration began to deliver on President Donald Trump‘s campaign promise to crack down on a work visa program that channels thousands of skilled overseas workers to companies across the technology industry.

Fed up with a program it says favors foreign workers at the expense of Americans, the Trump administration rolled out a trio of policy shifts. The U.S. Citizenship and Immigration Services agency on Friday made it harder for companies to bring overseas tech workers to the U.S. using the H-1B work visa.

Lottery Opens For High Skilled H-1B Visas

On Monday, April 3, as the H1-B lottery program for “high-skilled” worker visas opened with the 85,000 slots, the USCIS agency issued a memo laying out new measures to combat what it called “fraud and abuse” in the Program. The Justice Department further warned employers applying for the visas not to discriminate against U.S. workers.

Nearly three-quarters of the visas are expected to go to Indian workers, as they have in recent years.

“The Justice Department will not tolerate employers misusing the H-1B visa process to discriminate against U.S. workers,” said Acting Assistant Attorney General Tom Wheeler in a prepared statement. “U.S. workers should not be placed in a disfavored status, and the department is wholeheartedly committed to investigating and vigorously prosecuting these claims.”

The department’s U.S. Citizenship and Immigration Services will make unannounced site visits to companies that have a high ratio of workers on H-1B visas, and those whose foreign workers are outsourced to another company.

Seventy one percent of H-1B visa recipients came from India in 2015, according to a 2016 report by the U.S. Department of Homeland Security. China comes in second, accounting for nearly 10 percent of H-1B visa recipients.

India’s dominance of the H-1B visa system is cemented by the country’s giant outsourcing firms that submit tens of thousands of applications, increasing their chances of winning the coveted temporary work visas.

Among the top H-1B visa sponsors are Infosys, Tata Consultancy Services, Wipro, and Tech Mahindra Americas — Indian multinational corporations providing information technology and outsourcing services, according to Myvisajobs.com.

The outsourcing firms are controversial because they are exempt from the federal requirement that they not displace American workers if they pay H-1B visa holders at least $60,000 a year. That threshold still falls below the market rate for American tech workers.

American tech companies who use workers hired by these firms benefit from the cheaper labor, as well as the automatic loyalty engendered among workers who would otherwise lose their legal status.

The H-1B visas last for three years, and can be renewed once. But workers applying for green cards can renew their visas indefinitely. There is currently a decade-long backlog of Indian green card applicants. Given the tremendous delay, companies have an incentive to hire workers from India, who critics say end up in a system of de facto “indentured servitude.”