He has regularly vented his anger and frustrations on other posters. Cutting sarcasm is his favorite way of doing so.

I emailed him once because I found myself in the same position as he was.

I then sent one or two more polite emails, but said poster didn't reply. I think he dislikes/distrusts other foreigners in China. But then I noticed a lot of hatred/jealousy towards me from Canadians in China. Maybe they hate the people who gave them and spawned the language they teach.