"... Firstly, we made a big error. For this we are, of course, extremely sorry. The legacy customer database, with passwords stored in plain text, was a liability. Even though it wasn't active, it should have been deleted. There's no logical explanation for why it wasn't, other than as we moved off one project, and on to the next one, we dropped the ball and screwed up. ..."
Plain text for passwords fast, but not good.