I know this post is old, but I wanted to add to it and update.
I worked at Yale in Gumi for a period, I had been told about the attack, and since then the boss only hires men...

To add to the first post, he hasn't changed one bit. Jeong Dae Young was controlling, intrusive, often insulting and threatening. I also had many experiences of him just walking into my apartment while I was there, but more often than not, while I was downstairs teaching. What he did there is something I'll never know.

During my time there he created such a bad working atmosphere, although as is the case with most of these hagwon bosses, to begin with (the first 5 or 6 months) everything was fine, then his character and demands changed. By the 7th and 8th month he was intent on making my life miserable, often telling me to just quit and "leave my country". The mind games that he played were masterful, he's obviously had a lot of experience of making foreigners in Korea so miserable and reach the point of such despair that they do just leave in the night with him pocketing whatever money was left owed. I have plenty of stories that seem laughable now because they couldn't happen outside of a movie. There was the time he called the police on me for no reason (it's a small town and the main policeman was his friend)-I figured out then he was trying to intimidate me so I ran away.

The person before me lasted 2 months (I wasn't told this before I got there). To reiterate again the first post, the boss wouldn't allow me to have friends in my apartment, he also wouldn't let me have a social life and complained when I did see friends at the weekend, I assume now because they told me I shouldn't have to put up with and their bosses weren't like him.

I honestly wish I'd found postings like this before I went into Korea, my first job was a miserable time, although I did go to another one after and the overall Korea experience was a good one, if you get into a good academy. After my experiences there, I told my recruiters, they refused to send him any other teachers after that, which is something I assume he'd been told before, I get the feeling being blacklisted from one of the thousands of recruiters isn't something new to him.

If anyone is considering a contract offer from Yale Foreign Language Academy in Gumi, Korea, please look at other places first. Like I said, I spent a miserable time there and was also quite drastically out of pocket when I left.