As are services like Whispersystems RedPhone...
Why bother cracking RedPhone when you can just trigger something remotely on the completely unaccredited radio chip, or the SIM, or the OS platform itself. A modern phone does not have one operating system, but 3-4 and they all can - after you crack one - ask services freely from others.
The whole architecture of cellphones is so broken that installing RedPhone and thinking someone with resources can't do anything about it is plain laughable. Yes, it drops casuals and non-targeted attacks. But targeted? Never.