A computing paradigm based on the exchange and execution of arbitrary code is inherently risky.Yet, that’s pretty much the foundation of what we do today with personal computers. Consider that this model is the primary reason we pay billions of dollars to AV vendors to scan our machines for known malicious executable code. Consider that today most malware today is web-based – malicious executable code downloaded from the web onto the end-user’s machine and executed. In most cases, because the user was tricked into doing so. Sure, some baseline of local executables are needed for the OS and perhaps some personal productivity applications that require offline access. I can use whitelisting to control these. But do we really need the ability to download and install arbitrary executables for new types of functionality and services on our desktop?