I just went today. They copied the front and visa expiration page from passport and had me sign it before I could complete a withdrawal. This was at Bangkok Bank at Central Pinklao. It is something new, because I was not required to do this in the past. In fact, two months ago, when I went to the same bank, I withdrew 40,000 and they didn't require any copy of the passport pages. I asked why, and the teller said not needed on amounts below 50,000. But now it's needed.