With cashback Apps, take the cash out as soon as you reach their minimum amount. They can close your account anytime they want, and any balance you have with them is gone. You have no recourse as their word is final, they don't have to explain why and frequently won't. Also with Checkoutsmart and Quidco if you get kicked by one you will almost certainly be kicked by the other and loose both balances. Most people don't have problems, so it's just a way to minimise the risk.