At the start of the Trump administration there was tremendous media attention over the travel ban for nationals of several countries, but I pointed out at the time one of the lesser-noticed provisions was expediting implementation of exit controls at the border. This wasn’t just about keeping people out, it was also about keeping them in.
The plan has become more ambitious in fact a Department of Homeland Security report details the plan to require all departing passengers, including all citizens, to have photos (mug shots) taken when leaving the United States — expanding to land and sea crossings as well.