We can't have authors going around being immoral: it might interfere with the sales of their books. So HarperCollins have introduced a clause into their contracts to ensure that their authors don't do any dirty deeds, otherwise they will get their advances clawed back. Oh, only if the sales of their book have been harmed, of course.
What constitutes immoral behaviour and how you know that it affected book sales isn't spelled out. I guess HarperCollins think we can trust them to be the judge of that.
You can read more and see the actual contract clause at [E-Reads]. I found the story via the booktrade.info newsletter, which is a daily update of publishing news.
