Understanding Apple's legal brief in the FBI case

The fight between Apple and the FBI over the security protections on the San Bernadino iPhone has been fierce for the past few weeks, but it’s mostly been a PR battle thus far. From a legal and procedural standpoint, only two things had actually happened until yesterday: the FBI filed a motion to compel Apple to help it bypass security restrictions on the phone, and a magistrate judge ordered the company to comply. But yesterday Apple filed a motion to vacate judge Sherri Pym’s order, which lays bare the company’s actual legal argument against building a special one-off version of iOS that would allow the FBI to unlock the phone with a brute-force attack on its passcode.
So let’s pull it apart and see what’s going on here. While the PR machines on both sides are operating at full tilt, the actual substantive issue in this case is pretty simple: Does the government have the authority to order Apple to help unlock the phone based on statute or precedent? That’s the only question anyone’s trying to answer, since almost all the other facts in the case break decisively in the government’s favor: the government owned the phone, there’s a warrant, the guy was a terrorist asshole, etc., etc., etc. Apple doesn’t even really bring any of that up. The entire brief is focused on whether the government has the power to make Apple help law enforcement.
And reading through it, a few things are clear:

  1. This document feels hastily written and filed for the benefit of the press and public, not as a complete legal argument — it has typos, the language is surprisingly casual, and the arguments are ordered from easiest to understand to the most complex, not from strongest to weakest.
  2. An unspoken theme running through the entire brief is the fact that Apple is clearly happy to turn over the contents of iCloud backups to the government. This renders any real privacy claims moot; it's trivially easy to sketch out a legislative compromise where Congress will allow Apple to protect strong on-device encryption so long as every user is required to back their devices up to a server accessible to law enforcement.
  3. It will be surprising if the magistrate judge rules against the government on this set of law and facts by following Apple's complicated argument that relies on a close reading of a wiretapping statute from 1994, an interpretation of a 1977 Supreme Court case that itself interprets the All Writs Act from 1789, and lands squarely on major questions of First and Fifth Amendment jurisprudence. One way or another, this case will end up at the Supreme Court; whether or not the lower courts want to go out on a limb before that happens is totally up for debate.