netmeg - 1:40 pm on Nov 3, 2013 (gmt 0)
(b) require you to refund us within 30 days of any invoice, any amounts we may have overpaid to you in prior periods.
So I guess they could well bill you once you receive the payment, and stop all ad serving with adsense?
In theory, I guess they could. They obviously can't swoop down on your bank account and scoop out the funds, but I suppose they could turn you over to a collection agency (or call the law if some kind of click fraud were involved).
I've never heard of them actually doing that to anyone, and I hope I never do.