Just because a home computer might be hacked does not mean that an average user doesn't expect his experience on that computer to be private. Every area of life might be breached by determined intruders and, if that were the test of having a expectation of privacy, then every area of life would flunk it. Your home, your car, your bathroom, your bedroom, you name it. In reality, of course, break-ins, hacks, and other intrusions are the exception and not the rule in the areas we commonly regard as private. If the legal test on protecting privacy were to turn on whether break-ins or hacks were a regular element of the environment (however infrequent), then the exception swallows the rule and privacy is no more. This judge's ruling essentially embraces such logic and is thus wildly out of line with existing law regarding protection against unreasonable searches and seizures.
Also bad judging in reaching the issue gratuitously: the main issue here was whether a particular warrant was misused; it was unnecessary to decide what would have happened without a warrant of any kind. Yet the judge reached to inject his obiter dictum into the analysis as a sort of by-the-by, "here is what I would rule if other issues were before me."
Why such an outcome? As the lawyers say, "hard facts make for bad law." You have a despicable perp doing vile things and the natural instinct is to want to nail him. Just as, conversely, when you have a sympathetic person who has being seriously wronged, the natural instinct is to do what you can to help him get justice. In either case, judges and juries will be more prone than otherwise to engage in results-oriented jurisprudence and will thus try to bend and shape the law to that purpose even if the law objectively says otherwise. This factor may help explain why the judge did what he did. It does not make it right.
Finally, bad judging means, in this case, bad precedent and this decision will surely have pernicious effects until the day comes when its run is ended by a higher court. For this case, that day will surely come. It is a bad decision all around.