[P-Marlowe]

Had he done this on his own time, his own computer, and under simply his name without mention of the Marines, then he’d be in the clear.

Apparently that is what he did. The Marines didn't seem to care.

From the article:

Stein's lawyers countered that since the comments were made off-duty they are protected under constitutional guarantees of freedom of expression, saying the Marine Corps's own rules on the matter are vague.
They argued that restricting Marines from participating in political discussions essentially reduced them to second-class citizens.

[W. W. SMITH]

Hey......The big “O” put out the word “can no one rid me of this noisy noncom” and some perfumed prince undertook the task.

[xzins]

It is definitely a possibility that the hint in other articles that he had not done his blogging on his own computer and under his own name could be wrong. In my opinion, had he done this under his own name with no reference to his status in the Marine Corps and on his own computer, then he would be in the clear.

If he is still charged and tried even as one who has not over-stepped those guidelines, then the government is wrong in their prosecution of this Marine. The old standards might have been changed, but the old standards were an effort at preserving as much as possible of first amendment rights for the military.