So here is my problem. When kids join the military, they think that it is all free. That they get the free money, free training, free room and board, a pension, healthcare, all at taxpayer expense, for free. You don't. When in the military you boss is the POTUS, and you don't get to argue. You agreed with that when you accepted the above minimum wage paycheck for training. Also, according to what I read, you accept to be inactive duty for a number of years. I would also add that if you go around saying you are a decorated veteran, there is some responsibility to not act like a fool and disgrace that work.
This is true to some extent for any taxpayer funded job. If you are a teacher you can be let go for your facebook page. If you are a politician you can be forced to resign for your tweets. Taxpayer funded jobs are not like private jobs. They come with strings.
In this light let look at this case. This guy is a retired Marine, which means that he volunteered to serve his country, follow the chain of command, and accepted a pay check to do so. He is 26-27 so he is probably still on active duty. He is quoted as saying "I'm starting the Revolution. I'm done waiting." I don't know about you, but when a person trained in war says that they are going to start a revolution, that would make a little worried.
Note that such a thing is the basis for treason..."Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies, giving them Aid and Comfort. No Person shall be convicted of Treason unless on the Testimony of two Witnesses to the same overt Act, or on Confession in open Court."
My understanding he is being treated with kid gloves. He was held in a mental facility, instead of being charged with treason. If he is suffering from PSTD this is a good thing. Many vets do not get the help they need, and listening for these cries for help is something that the government should be doing.
In the end Facebook, despite what we want to believe, is a public venue and we should not be plotting revolutions using it. Everyone knows Twitter is where all the cool revolutionaries go. The government has some responsibility to monitor public communications to keep the country safe. This is one of the few enumerated roles of government, and is why this kid did not have to go out and find a real job. In this case, he many only be crazy as opposed to someone who would go into Time Square a shoot a dozen people. In either case, be it prevention or help, I don't see how this is a bad thing. If nothing else it is an example to kids that the military is not just playing soldier, it has some lifelong responsibilities.