First off, I definitely agree with the people who are saying he should have expected this, BUT..
This really bugs me, TECHNICALLY he endangered the US government, but in reality he had it in his head that the secrecy of this matter is ridiculous and the security and laws protecting it were irrelevant, so he really didnt really KNOW it was "wrong".
What is even worse is that nobody is on his side, nobody is trying to see it from his point of view, and unfortunately it appear most aspies have narrowed it down to "he broke the law" instead of feeling empathy for the one type of person that we really know.
BTW The government classifies all sorts of irrelevant things, mainly because the people making the decisions have such little technical knowledge of what they are classifying that they ignorantly classify things that are even public knowledge. For instance, if you look up any given military aircraft, lets say the military version of the Beechcraft King Air, you can easily find specs and pictures. Guess what? They still have a photo ban in place on this aircraft, any time one is on a base they inform any passerby that they may not take pictures. I have a friend who was shipping to Iraq and actually had this happen to him while he was boarding an airliner to head over there. Of course he took a picture of it just for the hell of putting it to the man. Its absurd, they even push publications like Janes to take down pictures of this aircraft. Their entry on the king air actually says its almost impossible to find a picture and so leaves one out. I find that ret*d, because you can google it and come up with dozens of pictures of even the most sensitive ELINT version of the aircraft.
I know that was way off topic, but it shows the sheer ignorance of some of the people in intel.
Im betting if McKinnon is a UFO nut that he did not know how insignificant most classified things are, and he is not a security threat in general, so prosecuting him is unfounded except under the mentality of "I told you so, except I didnt tell you so".
Some people say what he did was wrong and that he endangered the US, but the truth is that he did not, and nobody took hacking seriously until lately, the government has let hundreds, if not thousands, of hackers enter even the most sensitive nuclear labs. This has brought that to light more than ever.
Nobody did anything about it because people in the government simply do not care about anything except what is in their job description. They have the mentality that since its not under their control "its not my problem".
On top of that, I strongly believe that the prosecutors get personal satisfaction from dominating "lesser" human beings, they wouldnt be doing what they are doing if they didnt enjoy being able to put people "in their place".
I have strong feelings about this because my former best friend was a MA in the Navy, and I am closely related to a Captain in the JAG, and I have also had a chance to meet a few generals through the military ministry.
You have to remember that as analytical as we are about right and wrong and political situations, you have to factor in what you know about people and the emotional and ignorant responses, that the government is made of people and that they will do what we know any other person would do.