How to turn on Lockdown Mode on iPhone - so even the FBI can't get in

This ZDNET guide explains Apple’s iPhone Lockdown Mode—an extreme, reversible security setting intended for high‑risk users (e.g., journalists, activists) that significantly reduces attack surface by blocking most message attachments and link previews, restricting FaceTime from unknown callers, limiting advanced web tech and Apple services, removing shared albums, requiring unlock before wired connections, and blocking insecure networks; it allows limited per‑site/app exceptions, requires authentication to toggle, and reportedly thwarted FBI forensic access to a seized device, with step‑by‑step instructions for enabling, disabling, and managing exceptions.