Sam Lavigne, a far-left artist and game designer, is an adjunct professor at New York University’s Tisch School of the Arts. He created a database of 1,595 ICE employees using their LinkedIn profiles and shared it to his 3,600 followers on Twitter Tuesday morning. Antifa, the far-left organization labelled as “domestic terrorists,” picked up the database and spread it to their followers on Twitter hours later. The database also spread to a subgroup on Reddit that encourages spreading personal information — such as where they live and their contact information, known as “doxxing” — of people who they consider “Nazis”...