Apple, in refusing backdoor access to data, may face fines
zdnet.com
zdnet.com
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
Probable cause must precede the search & seizure of "papers" (presumably electronic messages are included by extension).
US Constitution Amendment III
No soldier shall, in time of peace be quartered in any house, without the consent of the owner, nor in time of war, but in a manner to be prescribed by law.
A reasonable interpretation includes ubiquitous monitoring of an individual without actionable cause. (As in: the "quartering" referenced has historically been used in part to monitor the home's occupants.)
US Constitution Amendment V
No person shall ... be compelled in any criminal case to be a witness against himself ...
Preemptively gathering (including tapping information storage for access on demand) broad-ranging evidence, before a criminal case is justified, is not justified. The enumerated right is moot if the government has preemptively aggregated everything that otherwise could be protected by this right.
In the case written about here, the Justice Department has a search warrant issued upon probable cause.