3_9_2014_ap130509062108201_s640x514The federal government has lost track of tens of thousands of foreign students who came to the U.S. to study and then took jobs, often in violation of the terms of their visas, according to a new internal audit. U.S. Immigration and Customs Enforcement doesn’t even consistently collect information or have the tools to monitor all of the foreign students who take part in the optional practical training (OPT) program, the Government Accountability Office said in a new report released late Friday. “The problems with OPT are extensive and serious. The report not only calls into question the department’s oversight of the program, but also whether such lack of oversight is a serious national security risk,” Sen. Charles E. Grassley, the Iowa Republican who released the report, said in a letter to Homeland Security Secretary Jeh Johnson. MORE