I was banned a long time ago, it was just before my 2nd payout. My guess is they just do the verification of the account before the payout, rather then just randomly throughout the cycle.
Right. It may not be that it is done maliciously, It could be related to the time it takes to notice strange activity, and then act on it. It also makes good business sense to review before a payment.
If there really was fraudulent activity it would be a bad idea to pay based on that.
One important issue that is also missing from this discussion is how Google refunds advertisers. I know I have heard from advertisers who got money back from click fraud.
