The Global Internet Forum to Counter Terrorism, launched in June by Facebook Inc., Microsoft Corp., Twitter Inc. and Alphabet Inc.’s YouTube, held its first meeting in San Francisco, Calif. Tuesday. Facebook said in a Monday press release that the meeting included “representatives from the tech industry, government and non-governmental organizations … coming together to share information and best practices about how to counter the threat of terrorist content online.” Representatives from Canada, along with those from Australia, the European Union and the United Nations,...