I was banned inexplicably from Adsense after several years. Really frustrating, particularly as it was two days before payday and they seized my earnings. Appeals were fruitless (and obviously it's difficult to appeal when you have no idea what they think you've done wrong). If Google continue down this flawed path and blocks publishers that haven't done anything wrong, they'll make a bad name for themselves. Hopefully unable to sit on their laurels for too much longer.