That depends on what was said. Social Media is a new world for the military and the rules are being tested every day. The military has released guidelines and even a Social Media Handbook to help Soldier navigate this new information world.
As long as your communication is private there is very little risk. Complaining to your family is one thing but blasting it to the public sector is another, especially if members of your unit can see it or the implication should the post go viral.