It is essential to this story that the order to Apple is not a
subpoena: it is issued under the All Writs Act of 1789, which says
that federal courts can issue “all writs necessary or appropriate
in aid of their respective jurisdictions and agreeable to the
usages and principles of law.” Read as a whole, this simply means
that judges can tell people to follow the law, but they have to do
so in a way that, in itself, respects the law. The Act was written
at a time when a lot of the mechanics of the law still had to be
worked out. But there are qualifications there: warnings about the
writs having to be “appropriate” and “agreeable,” not just to the
law but to the law’s “principles.” The government, in its use of
the writ now, seems to be treating those caveats as background
noise. If it can tell Apple, which has been accused of no
wrongdoing, to sit down and write a custom operating system for
it, what else could it do?
Lost amid the technical debate over encryption is the legal debate over this incredibly broad application of the All Writs Act.