A setting within Apple’s iOS, iPadOS, and macOS operating systems offers an extreme, optional security measure designed for a very small number of users who face grave, targeted digital threats. When activated, this mode severely restricts certain functions of the device to reduce the attack surface potentially exploitable by sophisticated spyware. For example, most message attachment types are blocked, web browsing is limited by disabling complex web technologies, and incoming FaceTime calls from unknown numbers are completely blocked.
The significance of this feature lies in its ability to provide enhanced protection against highly advanced and persistent threats, such as those posed by nation-state actors or mercenary spyware firms. It represents a direct response to the increasing sophistication of cyberattacks targeting individuals in high-risk situations, including journalists, activists, and political figures. The implementation provides a layered security approach, sacrificing some usability for a substantial increase in defense against potential intrusions.