Dan Guido, writing for Trail of Bits Blog, digs into the technical details of what the FBI is asking and whether Apple can do what the FBI is asking. This is a reasonably technical read, but the bottom line is this:

I believe it is technically feasible for Apple to comply with all of the FBI’s requests in this case. On the iPhone 5C, the passcode delay and device erasure are implemented in software and Apple can add support for peripheral devices that facilitate PIN code entry. In order to limit the risk of abuse, Apple can lock the customized version of iOS to only work on the specific recovered iPhone and perform all recovery on their own, without sharing the firmware image with the FBI.

This analysis is worrisome. It digs into the “can they” but not the “should they”. It points to the tip of a very slippery slope. If Apple can be forced to custom-hack a single phone, what comes next? Will Apple be forced to open a shop dedicated to one-off phone hacking? Will they be forced to create a tool to make this task simpler? Will they come for my phone? For yours?