[pcwalton]

> Instead of $200 billion in the bank, unspent, shouldn't those devices be reviewed and redesigned until impregnable?

The problem is the Mythical Man-Month. Apple's devices are built on a mountain of ancient C code. XNU is a bizarre Mach/BSD hybrid, built for the sake of expedience. (This is not to bash Apple; most other devices aren't much better.)

Apple has been working to improve the situation, but there's a limit as to how rapidly all those millions of lines of code can be changed.