Yes,indeed he need to learn how to write properly and other than that this forum created to discuss not to curse someone or even 'the president'.
They're arrested him because he's running an exchanger for doing a money laundry,and any other crime.
But your statement :
He's a hacker was wrong,he's not the hacker but he's involved in hacking Mt.Gox (they said,which mean it's not proven yet so far).
from that point we can see he's not the hacker but he's the money launderer.
From my perspective his guilt(obviously i selectively a possible crime that he did from their statement) were money laundry,involved in hacking Mt.Gox,illegal exchanger and activity