I touched on the Quon case very briefly in the past. Despite the received wisdom that employers are within their rights to access resources they provide to employees, there was still some strong speculation this case, on being heard by the Supreme Court, might yield some changes, good or bad, on certain 4th Amendment questions.
EFF has an optimistic analysis of the ruling just handed down. As Kevin Bankston explains, the danger in this case would be that a ruling be too rashly made that would inadvertently weaken 4th Amendment protections. The court instead stuck to the question of whether the employer, the City of Ontarion, was within its rights, which they answered in the affirmative. They carefully avoid the question of the 3rd party storage and service involved. Had they touched on that aspect, it could have much broader ramifications so I can see why EFF thinks this is a good, considered ruling.
From the decision:
The Court must proceed with care when considering the whole concept of privacy expectations in communications made on electronic equipment owned by a government employer. The judiciary risks error by elaborating too fully on the Fourth Amendment implications of emerging technology before its role in society has become clear. See, e.g., Olmstead v. United States, 277 U. S. 438 (1928) [finding that warrantless telephone wiretapping did not violate Fourth Amendment], overruled by Katz v. United States, 389 U. S. 347, 353 (1967). In Katz, the Court relied on its own knowledge and experience to conclude that there is a reasonable expectation of privacy in a telephone booth. See id., at 360–361 (Harlan, J., concurring). It is not so clear that courts at present are on so sure a ground. Prudence counsels caution before the facts in the instant case are used to establish far-reaching premises that define the existence, and extent, of privacy expectations enjoyed by employees when using employer-provided communication devices.
Frustrating to some hoping for some motion to bring case law up to date with the current state of technology, I have to side with Bankston and EFF on this, that the precautionary principle is a wise course when there are so may potential counter intuitions and latent ambiguities exposed by the rapid pace of change.