Now more than ever, it is apparent that U.S. Customs and Border Protection (CBP) and its parent agency, the Department of Homeland Security (DHS), are embarking on a broad campaign to invade the digital lives of innocent individuals. The new DHS secretary, John Kelly, told a congressional committee this week that the department may soon demand login information (usernames and passwords) for social media accounts from foreign visa applicants—at least those subject to the controversial executive order on terrorism and immigration—and those who don’t comply will be denied entry into the United...