Nah, would a spambot keep a journal?
My money's on the idea that he's been hypnotized to do this.
I'm not necessarily betting that that's the case, but I do think it's possible that that's what he wants us to think. So either of those.
When I first saw these posts, I got the idea that this was some child without adequate parental supervision that somehow stumbled onto this site. He doesn't really know what's going on, and as a result, posts a lot of gibberish. Of course, it's always possible that someone older is impersonating this, but I'm not going to come to any conclusions until more evidence is available.