Patching memory at runtime on an iPhone is not in any sense "easy". If it were the FBI wouldn't need Apple's help right now at all; they could just NOP out the

Patching memory at runtime on an iPhone is not in any sense "easy". If it were the FBI wouldn't need Apple's help right now at all; they could just NOP out the code that implements the increasing timeout and erase-on-too-many-failures code. To put it another way – if it were in fact easy to patch memory at runtime, there would be no need for the jailbreak community to spend huge amounts of time and effort every new OS release.