Around 06:30 Eastern time Feb. 2, approximately 13,000 Army inboxes pinged with an email from an unfamiliar sender. It was from a U.S. Army captain, asking to be removed from a distribution list. It initially seemed as though some unfortunate soul had inadvertently hit "reply-all" and made an embarrassing mistake. What followed can really be described only as professional anarchy, as thousands of inboxes became buried in an avalanche of email replies.