The key thing to remember here is that Acrio isn't some maniacal supervillain, or fascist dictator. He is merely a troll who wants to get some attention. There was no skill or talent involved in his shenanigans; he was merely in a position where he could take advantage of the trust of many who, even after his repeated attacks on the integrity of the Mobius Forum, still gave him more chances. He had people who enabled him. Without them, he wouldn't have had enough influence or power to do anything.
Look at the contributions Acrio made to the forum over the last several years, and you will find very little that he himself actually created. No great works of art or writing, very little in the way of programming, and in general no really pertinent or important posts. And in the end, he has ensured that no one who knows who he is will trust him. He has punished himself; yes, he's disrupted the forum, but he cannot stop us from building again, from regrouping.
He's just a troll. There is nothing more to fear as long as good people stand up and do not allow their trust to be abused again.
And, what Sam said. It is supremely debatable whether Acrio was sane to begin with. There are many good people on the staff who, even when given full power and control on Yuku, used their powers only as necessary and just.
I'd change any passwords that you may have used at the board, though, if you have used them anywhere else. Just a word to those who may not have been wise in selecting a password for the board in the first place.