> The controversy here from a legal standpoint is that what's being asked of Apple is too burdensome. I don't really know the constitutional argument against burden (probably the 10th, limiting the power of federal government), but there seems to be some.
There's more to it than that, and I'd argue that the primary controversy in this case, and to an extent even in the San Bernardino case (where the burden is certainly higher than here), burden isn't the primary controversy.
Basically, for the AWA to apply there are 3 statutory "tests" that have to be met that are laid out in the AWA itself, and 3 more discretionary "tests" that derive from the Supreme Court ruling in US v New York Telephone Company that control when a judge should exercise their discretion to issue an AWA writ (because these writs are never mandatory).
The statutory tests are: 1. Jurisdiction, 2. Necessity and appropriateness to aiding the court's jurisdiction, and 3. Agreeableness to the principals and usages of law.
The discretionary tests are: 1. Closesness of the target of the writ to the matter at hand (crime, civil action, etc), 2. Burden the writ imposes, and 3. Necessity (which overlaps the statutory test, but is more broadly interpreted).
This ruling doesn't just say the proposed use here of the AWA fails the burden test, it says it fails the 3rd statutory test and ALL the discretionary tests.
And this is where I'd argue the real controversy here derives from the 3rd statutory requirement. The Government's argument is, essentially, that any use of the AWA is agreeable with the usages and principles of law, as long as no law specifically forbids that use.
This is what is seen as controversially expanding the scope of the AWA to a massive degree. The Government's argument that Judges can only consider what the legislature has explicitly banned, not what the legislature failed to take up (like the fact that congress declined to give police agencies these powers in CALEA), has the effect of turning the AWA from an innocuous "paper the gaps" rule, into a statute of enormous, practically unlimited power.
As this ruling points out, if there were a law under consideration by congress that required, say, Drug Manufactures to produce lethal injection drugs, and every single member of congress voted against the law, the government's argument claims that they could still use the AWA to force a company to do exactly that and that it would be completely agreeable with the usages and principals of law, despite clearly thwarting the will of the legislature. Rather than decline to pass laws whose power congress dislikes, congress would actively have to pass laws forbidding every such power, or the AWA could be used to confer it, in the interpretation advanced by the Government here.
Essentially the interpretation the Government is advancing would require congress to blacklist everything under the sun, or its all fair game under the AWA. This interpretation, the ruling argues, would probably render the AWA unconstitutional if followed.
And that's the controversy. The Obama administration just declined to seek expanded powers encryption-thwarting powers for the FBI via the legislature. The FBI is now undertaking to "find" those same powers in an expansive new interpretation of the AWA.
tl;dr it's not just that it's too burdensome, it's that it tortures the meaning of the AWA to assume it applies this broadly to areas the legislature has already declined to grant power, the case is too narrowly connected to Apple, it's not clear that the Government has no other means it could have used to meet the goal, and it's too burdensome