This is all speculation, since the only person who can answer authoritatively is dead. I think that he honestly believed that it would be no big deal. If you read comments here on HN, you can see the same attitude - that since there was no real security, it wasn't a crime, since he didn't lie to anyone they couldn't claim he misrepresented himself to get access, etc. I think that Aaron honestly believed that what he was doing was "hacking the legal system" - accomplishing his goal by exploiting loopholes in the law rather than breaking it.
What he found out was that the people in the legal system do not take kindly to being "hacked". Rather than give a wry smile and say "You got us this time, Aaron Swartz!", the prosecutor grabbed on to the part that she thought she could make stick and went for it. The rest is, as they say, history. There are a lot of lessons in what happened, but one that I haven't seen get much mention here on HN is that the US legal system is comprised of people, with all the advantages and disadvantages that that entails. It's not something that should be "hacked" lightly or by the unprepared, because the consequences are not always as deterministic as you might think they should be.
On a side note, I think your comment about HN being "abusive" lately is spot-on. Some of the discussion has bordered on "internet lynch mob", and I can't say I'm very comfortable with that regardless of the circumstances.
What he found out was that the people in the legal system do not take kindly to being "hacked". Rather than give a wry smile and say "You got us this time, Aaron Swartz!", the prosecutor grabbed on to the part that she thought she could make stick and went for it. The rest is, as they say, history. There are a lot of lessons in what happened, but one that I haven't seen get much mention here on HN is that the US legal system is comprised of people, with all the advantages and disadvantages that that entails. It's not something that should be "hacked" lightly or by the unprepared, because the consequences are not always as deterministic as you might think they should be.
On a side note, I think your comment about HN being "abusive" lately is spot-on. Some of the discussion has bordered on "internet lynch mob", and I can't say I'm very comfortable with that regardless of the circumstances.