There must be some serious credible threat if they issued a worldwide message.
As Reported by The Washington Times:
The U.S. Army has issued a worldwide urgent “security awareness message” to soldiers on how to protect their social media accounts, and their homes, from attacks by the Islamic State terrorists or other extremists.
The message lists over a dozen safety steps, including to make sure personnel check the door peephole before letting someone in their homes, to fortify doors, to hold family meetings on security and to greatly tone down social media postings so terrorists do not know personal connections or daily comings and goings.
The Army issued the warning on Friday in reaction to the Islamic State, also called ISIL and ISIS, publishing the names of 100 U.S. military personnel as targets for assassination.