This interface is implemented by components to enable privileged code to check whether the component has a given permission. This is typically used when a privileged component (e.g. the container) is performing an action on behalf of an untrusted component (e.g. a web application) without the current thread having passed through a code source provided by the untrusted component. Because the current thread has not passed through a code source provided by the untrusted component the SecurityManager assumes the code is trusted so the standard checking mechanisms can't be used.