The government has surely tapped phones, internet actions and messenger discussions without us knowing about it and as long as we're not doing anything illegal this should not bother us. The war on terror is more important. Concerning credit cards, the banks might have some sort of confidential contract with the client but when the law wants some info that confidential contract is violated. Terrorist can be tracked or monitored by watching their debt settlement and transactions. Hell, we all can be monitored like this. To be invisible means to have cash and spend it in different places, the series on the bill must not be consecutive and so on.