WARNING:
This happened to me, as well as a few other people who I've met in Korea. (Apparently it must have been a bigger problem in years past...anyways)
When I first came to Korea, I was told by my recruiter to take a bus to the city in which I was going to (around Suwon) and that he would pick me up at the bus terminal. When I landed, as soon as I picked up my baggage, I was immediately approached by an older man who spoke decent English. He asked me if I was a new English Teacher and I said yes, he then told me to come with him and that my school had arranged for him to pick me up. Right from the get-go, I thought this was a tad bit weird, since the recruiter had told me otherwise in the emails. Anywho, in my jet-lagged state, I went with him, and he took me to his private van. Now, I had done enough research about Korea to know about how much it was going to cost me to get from the airport to where I needed to go, even in a Taxi, after about five minutes he asked me if I was going to be using cash or card..and whipped out the little card machine. I asked him how much it was going to be? 250,000won! This is when the red flags started going up, and I demanded him take me back to the airport immediately.
Looking back on it, it was extremely naive of me to even get in the van with him, however, after I asked around, I learned that other english teachers had fell victim to people like this, and that some of them are actually successful into dooping newbies out of money. Apparently they're gangs who go around and try to snatch up anybody who looks confused as to where they are supposed to go.
Just a fair warning.