Operations security (OPSEC) is a process that identifies critical information to determine if friendly actions can be observed by adversary intelligence systems, determines if information obtained by adversaries could be interpreted to be useful to them, and then executes selected measures that eliminate or reduce adversary exploitation of friendly critical information.

(Courtesy wikipedia: http://en.wikipedia.org/wiki/Operations_security)

Remember OPSEC while communicating through Military Jeepers. Do not mention movement times, locations or other information which could be used by the enemy. Your one piece of information may not seem like it would be valuable to the enemy, but combined with other open source information it could tell them a lot about your unit, missions and other information which could put lives at risk,

National OPSEC Program: http://www.ioss.gov/

OPSEC a Guide for Family and Friends (PDF File): http://www.armymedicine.army.mil/sfrc/OPSECTrifold.pdf

Keep Your Family Safe: Practice Operational Security on Social Media: http://www.navy.mil/search/display.asp?story_id=50450