Yesterday, Harrison Rudolph, a law fellow at the Center on Privacy & Technology at Georgetown Law, wrote a very troubling article at Slate titled, DHS Is Starting to Scan Americans' Faces Before They Get on International Flights. Here's some of what we learned:

Decades ago, Congress mandated that federal authorities keep track of foreign nationals as they enter and leave the United States. If the government could record when every visitor stepped on and off of U.S. soil, so the thinking went, it could easily see whether a foreign national had overstayed a visa.

But in June of last year, without congressional authorization, and without consulting the public, the Department of Homeland Security started scanning the faces of Americans leaving the country, too.