Following a closer look at immigration policies after the mass shooting in San Bernadino, Calif., it has come to light that the U.S. Department of Homeland Security has only a rough estimate of how many foreign travelers have overstayed their travel visas. Officials claim that the insufficient data stems from a lack of advanced data collection technology, resistance from airline and tourism industries, and questions regarding how useful tracking people exiting the country is as an anti-terrorism measure. For more information, click here.
