If one doesn't separate the human from the endpoint system e.g. which is what client side security is really all about, then - and only then - will we make progress in the IT security battle. The human, peripherals and machine comprise the client side endpoint which needs to be protected in its entirety! Now let's think about Integrity, Availability and Confidentiality again.
Aside: Lines are being blurred between the conceptual client and server roles each day. Service orientated enterprise architectures are only a minor part of the puzzle... Let us never forget the users, administrators, operators and developers as part of the overall puzzle. (Or is it a mystery?)