The Department of Homeland Security has issued a report that says 527,127 aliens illegally overstayed their visas last year, while 482,000 are believed to be still in the country.

Last year there were 219 illegal overstays from Afghanistan, 681 from Iraq, 564 from Iran, 56 from Libya, 1,435 from Pakistan, 440 from Syria, and 219 from Yemen, according to the report. Many are still in the United States illegally. The statistics also do not encompass land ports, meaning those numbers compiled from Latin American could be higher as result of these types of border crossings. The 527,127 individuals found by DHS to have overstayed their visas account for 1.17 percent of the “44,928,381 nonimmigrant admissions to the United States for business or pleasure” in 2015, according to the report. “There were 482,781 Suspected In-Country Overstays,” according to DHS. “The overall Suspected In-Country Overstay rate for this scope of travelers is 1.07 percent of the expected departures.”

Do you think it's possible to overstay your visa in Russia? China? North Korea? Perhaps, but clearly it isn't as easy as it is in the U.S. Apparently, U.S. immigration authorities make little effort to track visa holders. And the question Congress wants answered: Is this deliberate?

The Senate Immigration Subcommittee is schedule to hold hearing Wednesday to investigate this issue. Testimony will be provided from officials from U.S. Customs and Border Protection, as well as U.S. Immigration and Customs Enforcement. Lawmakers on the committee remain concerned that the Obama administration has implemented a de facto policy of exempting visa overstays from its enforcement regime. “By not enforcing visa overstays, the administration has flung the border open—millions get temp visas and then freely violate their entry contracts and shred their eviction notices,” the subcommittee said in a statement. “Further, DHS has refused to complete the legally required biometric tracking system.”

It would be in keeping with the philosophy of the Obama administration that we don't track visa holders or those from countries that are in the visa waiver program. It is also SOP for Obama not to mention it to Congress or the American people.

But considering that most of the 9/11 terrorists overstayed their visas, it might be in the national interest to do a much better job tracking visa violators – especially from countries where terrorism is a problem.