Justice Karakatsanis wrote as follows (at paras. 2-4, 47, 56, 64-65, 67):

"Section 8 of the Charter protects all Canadians against unreasonable search and seizure. In assessing whether s. 8 has been infringed, courts consider whether an individual’s privacy interests must give way to the state’s interest in law enforcement. The challenge of s. 8 is that courts are most often called on to interpret its scope in cases, like this, where the police have found evidence that the claimant has engaged in criminal activity. Child pornography offences are serious and insidious, and there is a strong public interest in investigating and prosecuting them. However, in applying s. 8 , the question is not whether the claimant broke the law, but rather whether the police exceeded the limits of the state’s authority. The answer in this case impacts not only Reeves, but also the privacy rights of all Canadians in shared personal computers.

The judge hearing the Charter application concluded that the police infringed Reeves’ s. 8 Charter rights, and excluded the child pornography evidence under s. 24(2) (2015 ONCJ 724). Reeves was acquitted at trial. The Court of Appeal did not agree with the application judge that the police infringed s. 8 when they took the computer with the consent of Reeves’ spouse (2017 ONCA 365, 350 C.C.C. (3d) 1). It allowed the appeal, admitted the evidence, and ordered a new trial.

I agree with the application judge that the police infringed Reeves’ Charter rights when they took the computer from his home, and that the child pornography evidence should be excluded. Although the computer was shared, Reeves maintained a reasonable expectation of privacy in it. The consent of Reeves’ spouse did not nullify his reasonable expectation of privacy, or operate to waive his Charter rights in the computer. The warrantless seizure of the computer and the search of it without a valid warrant were unreasonable, and the admission of the child pornography evidence would bring the administration of justice into disrepute.

...

In short, in light of the deeply intimate nature of information that can be found on a personal computer, Reeves’ subjective expectation of privacy was objectively reasonable. His spouse’s consent could not nullify his reasonable expectation of privacy in the computer data. Indeed, both the Crown and the Court of Appeal appear to have recognized that Reeves had a reasonable (although diminished) expectation of privacy. While Reeves’ reasonable expectation of privacy in the computer was limited, given that he shared control over the computer with his spouse, it still suffices to trigger the protection of s. 8 of the Charter (see Buhay, at para. 22). Indeed, “[a] reasonable though diminished expectation of privacy is nonetheless a reasonable expectation of privacy, protected by s. 8 of the Charter ” (Cole, at para. 9).

...the taking of the computer without Reeves’ consent interfered with his reasonable expectation of privacy and thus constituted a seizure within the meaning of the Charter (Cole, at para. 59). A warrantless seizure is presumptively unreasonable, and the burden falls to the Crown to rebut this presumption (Hunter, at p. 161; Monney, at para. 29). Indeed, because someone is always likely to have a reasonable expectation of privacy in a personal computer, the taking of a personal computer without a warrant and without valid consent will constitute a presumptively unreasonable seizure. The Crown has not endeavoured to rebut the presumption in this case, as it relies on Gravelle’s consent to show that no seizure occurred.

...

Additionally, as in Morelli, the ITO upon which the search warrant was obtained was “[a]t best . . . improvidently and carelessly drafted” (para. 100). The application judge concluded that the computer search breached the Charter because the ITO reflected “‘a goal-oriented, selective presentation of the facts’ that resulted in an ‘unfair, unbalanced and misleading’ portrayal of the applicant” and was insufficient to have justified granting the warrant (para. 38).

In short, there were serious Charter breaches throughout the investigative process. Overall, the police conduct in this case undermined “public confidence in the rule of law” and favours exclusion of the evidence (Grant, at para. 73).

...

With respect to society’s interest in the adjudication of this case on its merits, I agree with the application judge that it was strong. The unconstitutional search and seizure of the computer revealed reliable evidence that was important to the prosecution’s case (see Grant, at paras. 81 and 83). Further, as the application judge and the Court of Appeal both noted, the alleged offences were serious. Child pornography offences are “particularly insidious” (Morelli, at para. 8). Cases in which a court must decide whether to exclude probative evidence of a serious crime are always challenging. However, the seriousness of the offence “has the potential to cut both ways” in assessing whether evidence should be excluded (Grant, at para. 84; see also Paterson, at para. 55). Indeed, “while the public has a heightened interest in seeing a determination on the merits where the offence charged is serious, it also has a vital interest in having a justice system that is above reproach” (Grant, at para. 84)."

Note: The summary and body are drawn from Eugene Meehan’s SupremeAdvocacy Weekly Updates for the Law Community.