Looking at ha1tru0n9, it seems like he exists merely to answer Hai Truong's questions. This seems dodgy, but I'm not sure if it's forbidden, so I thought I'd draw it to the moderators attention.
Yes, it is forbidden to create multiple accounts (called sock puppets) to answer your own (or in fact anyone's) questions in order to deposit votes for a reputation boost.1 As mentioned by the answer to
Possible sockpuppet - What's the procedure?
... the optimal course of action is to flag one of the user's posts for moderator attention, which sends a message directly to us so we can handle it as quickly as possible.
That said, we've handled the case, since you've posted here on meta. Thanks for bringing this to our attention.
1 Not only is reputation quite easily earned through honest and sincere involvement with the community, but it is also not necessary to create a different account to answer your own question.