The federal government has created yet another immigration employment hurdle for U.S. science, technology, engineering and math (STEM) workers, according to a new report. After obtaining data through a Freedom of Information Act request, a Pew Global analysis of Immigration Customs and Enforcement (ICE) data showed that almost 1.5 million foreign students have been allowed to stay and work in the U.S. after graduation as part of the little-known work program, the Optional Practical Training program (OPT). ICE is the federal agency that oversees, ineffectively, the Student and Exchange Visitor Program.Since 2008, the number of STEM students using OPT has increased a staggering 400 percent.