No doubt you’ve heard that a chain is only as strong as its weakest link. In the world of electronic funds transfers, this maxim holds doubly true. It applies to security systems and the networks they run on (including the Internet) as well as the users of those systems and networks. A security system can only defend a network if it offers sufficient coverage and controls. Absent such controls, users can, intentionally or accidentally, access, change or steal data that they are not authorized to see.