Is it possible to make a Linux security module (eg. AppArmor, SELinux etc.) prompt the user, when an application wants to access classified files or folders (digital signatures, SSH keys, credit card information and other sensitive stuff) instead of just denying the application's action, which could be desired (eg. an email client wanting to sign an email on the user's request).
It will be beneficial to set up strict default security policies for vulnerable applications (especially web browsers and email clients) and let the user decide, whether a given action is desired or not, so vulnerability of the system can be avoided without worsening the user-friendliness.