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When Can Wisconsin Police View Your Snapchat or Phone Content Without a Warrant?

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On January 14, 2026, the Wisconsin Supreme Court answered a question that reaches far past the facts of any one case: when a private company’s automated system flags something on your phone or in your cloud account, can police view the flagged item without a warrant? In State v. Gasper, 2026 WI 3, the answer was yes, under the right facts, and the case is now sitting in front of the U.S. Supreme Court on a pending petition for certiorari. Here is what the doctrine actually says, what the Wisconsin court held, and what it means for anyone whose phone, Snapchat, Dropbox, or cloud account gets flagged by a platform’s scanning software.

The Private Search Doctrine, In Plain English

The Fourth Amendment restricts what the government can search without a warrant. It does not restrict private companies. When a private party, like a tech platform, searches something and turns over what it found to police, the government generally does not need a warrant to look at exactly what the private party already found, because your expectation of privacy in that specific material was already lost when the private search happened. This is the “private search doctrine,” and its foundational case is United States v. Jacobsen, 466 U.S. 109 (1984): FedEx employees accidentally damaged a package, opened it under company policy, and found bags of white powder. When a DEA agent field-tested the powder without a warrant, the Supreme Court held that was fine, because there was “virtual certainty” the test would reveal nothing beyond what FedEx’s employees had already found.

The doctrine has a real limit, though, established in Walter v. United States, 447 U.S. 649 (1980). There, a company received misdelivered film reels, glimpsed only “suggestive” content by holding strips up to light, and turned the boxes over to the FBI. The FBI then projected and reviewed the films with a projector over two months. The Supreme Court held that was an unconstitutional expansion of the private search, because the private party had only inferred what might be on the film. The government’s review went well beyond what had actually been revealed.

The test that separates a lawful “re-creation” of a private search (Jacobsen) from an unlawful expansion of it (Walter) is whether there is “virtual certainty” that the government’s viewing will disclose nothing more than what the private search already revealed.

What Actually Happened in Gasper

In January 2023, Snapchat’s automated scanning system, Microsoft’s PhotoDNA, flagged a single 16-second video uploaded to a user’s account as matching known child sexual abuse material (CSAM) through a hash-value comparison. No person at Snapchat viewed the video. Snapchat’s system, as federal law requires of platforms that detect apparent CSAM, forwarded a CyberTip and the flagged video to the National Center for Missing and Exploited Children, which likewise confirmed the hash match without human viewing and forwarded the tip to the Wisconsin Department of Justice. A DOJ analyst then opened the video without a warrant to confirm it was CSAM, obtained the account holder’s identity through an administrative subpoena to the internet service provider, and referred the matter to the Waukesha County Sheriff’s Office, where a detective also viewed the video without a warrant before applying for a search warrant of the suspect’s home and phone. That search recovered ten additional files, leading to state charges for possession of child pornography and sexual exploitation of a child.

The defendant moved to suppress all of the evidence, arguing that because no human being at Snapchat had ever actually looked at the video, the government’s viewing of it, without a warrant, was not a “re-creation” of a private search at all. It was the first search. The circuit court agreed and suppressed the evidence. The court of appeals reversed on different grounds, holding the defendant had no reasonable expectation of privacy in the video given Snapchat’s terms of service. The Wisconsin Supreme Court then took the case to resolve the private-search question directly.

What the Wisconsin Supreme Court Actually Held

Writing for a five-justice majority, Justice Annette Kingsland Ziegler held that the private search doctrine applied and affirmed the result (no suppression), though on different reasoning than the court of appeals had used. The core of the majority’s analysis: Snapchat’s automated hash-matching scan was itself a private search, even though no human viewed the video, because the private search doctrine has never required human eyes, only that a private actor examine the material and reach a conclusion about it. Because PhotoDNA’s hash-value comparison identified the video as CSAM with what courts have called “almost absolute certainty,” the government’s subsequent viewing of the same single video was, in the majority’s words, a “virtual certainty” to reveal nothing beyond what Snapchat’s scan had already reported. On that reasoning, the case looked more like Jacobsen (confirming what a private search already established) than Walter (expanding into territory the private search never actually revealed).

The Wisconsin court explicitly rejected the approach taken by the Second and Ninth Circuits in United States v. Maher, 120 F.4th 297 (2d Cir. 2024), and United States v. Wilson, 13 F.4th 961 (9th Cir. 2021), both of which held that police viewing flagged files exceeds the scope of an automated scan because a human viewing reveals “particulars” the hash match alone did not. The Wisconsin majority sided instead with the Fifth and Sixth Circuits, in United States v. Reddick, 900 F.3d 636 (5th Cir. 2018), and United States v. Miller, 982 F.3d 412 (6th Cir. 2020), which treated a validated hash match as functionally equivalent to a human viewing for private-search purposes.

The Court Was More Divided Than the Vote Count Suggests

This is the part that matters most for defense practice, and it rarely makes it into press coverage of the decision. Five justices joined the majority opinion, but two of them, Justice Rebecca Dallet and (in part) Justice Susan Crawford, wrote separately to say they did not think the private search doctrine actually covered what happened here. Dallet argued that a private company’s terms of service cannot eliminate a user’s constitutional expectation of privacy against the government, and that viewing the video revealed “innumerable granular private details” the hash match alone had not. She concluded the evidence should still not be suppressed, but only because the detectives acted in good-faith reliance on the (at the time) weight of non-binding authority favoring the state’s position, the good-faith exception to the exclusionary rule, not because the private-search doctrine actually applied.

Justice Crawford went further in her partial dissent, agreeing with Dallet that the private search doctrine did not cover the warrantless viewing and that the good-faith exception did not save it either, because the law was genuinely unsettled and the state easily could have obtained a warrant instead of taking that risk. Crawford would have suppressed the video itself. She concluded, however, that the CyberTip and the surrounding investigative information independently supported probable cause for the search warrant of the defendant’s home and phone, so the ultimate evidence recovered from that warrant did not need to be excluded as fruit of the poisonous tree.

In other words: on the narrow question of whether an automated hash-match scan is legally equivalent to a human private search, the justices split closer to 5-4 than the clean majority opinion suggests, with real, reasoned disagreement about where the line actually sits.

Where the Line Still Holds

Gasper is not a blanket rule that any tech-platform tip lets police view anything they want without a warrant. The private search doctrine’s outer boundary from Walter is still good law, and the Gasper majority took pains to note the limits of its own holding:

  • The government cannot view more than what the private search covered. Gasper did not argue that police viewed additional files or learned anything beyond the single flagged video. If a case involves police reviewing content beyond what the automated system actually flagged, or scrolling further into an account than the private search reached, the Walter line still requires a warrant for that expansion.
  • “Virtual certainty” is a real, factual requirement, not a formality. The majority relied heavily on unchallenged testimony that the scanning technology (PhotoDNA specifically) reliably identifies known CSAM. A case built on a less validated or more error-prone scanning technology, or one where the defense can show a meaningful risk of a false match, presents a materially different record than Gasper.
  • The good-faith exception is not permanent cover. Justice Dallet’s concurrence rested on law enforcement’s reasonable reliance on unsettled, non-binding precedent at the time. Now that Gasper itself exists as binding Wisconsin precedent, that particular good-faith argument gets weaker for future cases, not stronger, at least until the circuit split is resolved at the federal level.
  • Independent, untainted evidence can still support a warrant even where suppression should apply, as Crawford’s opinion illustrates. That cuts against defendants in some fact patterns and underscores why the specific content of a CyberTip, not just the flagged file itself, matters in every one of these cases.

Why This Is Bigger Than One Case

The private search doctrine question in Gasper is not limited to Snapchat or to CSAM investigations. The same automated-scanning architecture, hash matching, machine-learning content classification, and mandatory reporting obligations under 18 U.S.C. § 2258A, runs across cloud storage, email, messaging apps, and social platforms generally. Any of it can generate a tip that leads to a warrantless government viewing under the same doctrine Gasper applied. That is precisely why the case attracted an amicus brief from the Project for Privacy & Surveillance Accountability when it reached the U.S. Supreme Court, and why the underlying legal question, not the specific facts of any one prosecution, is what makes this worth tracking.

The Case Isn’t Over

Gasper petitioned the U.S. Supreme Court for a writ of certiorari, docketed as Gasper v. Wisconsin, No. 25-1191. Wisconsin filed a brief in opposition on June 1, 2026, after initially waiving its right to respond and then being asked by the Court to do so. As of late July 2026, the petition is scheduled for the Court’s conference on September 28, 2026. Because Wisconsin’s decision sided with the Fifth and Sixth Circuits against the Second and Ninth Circuits on a live, acknowledged federal circuit split, this is exactly the kind of case the Supreme Court sometimes takes up to resolve. Nothing changes for pending Wisconsin cases unless and until that happens, but a grant of certiorari would put the entire private-search-doctrine question for automated content scanning back in play nationally.

What This Means If You’re Facing a Case Built on a Digital Tip

If a case against you started with a tip from a tech platform, whether it involves a phone, a cloud account, a messaging app, or a social media platform, the analysis a defense attorney should run now includes:

  • What exactly did the private scan flag, and did the government’s viewing stay within that scope?
  • What scanning technology was used, and is there a real basis to question its reliability in this specific case, not just in the abstract?
  • Did law enforcement rely on a warrant, an administrative subpoena, or nothing at all to identify the account holder, and was each step properly documented?
  • Is there independent, untainted evidence supporting any subsequent search warrant, separate from the initially viewed material, the way Justice Crawford analyzed in her Gasper dissent?

These are fact-intensive, record-specific questions, and Gasper shows that even Wisconsin’s own Supreme Court did not agree on how they come out. That is exactly the kind of unsettled ground where a careful, early defense review matters most.

For related reading on how social media and digital evidence show up in Wisconsin criminal cases, see our posts on how the police and prosecutors use social media, why anything you post can become evidence, and our social media and criminal defense infographic. For the broader doctrine on what police can and cannot do with evidence obtained through a questionable stop or search, see Police May Use Evidence Found After Illegal Stops.

If you are facing charges that started with a tip from a phone, app, or cloud platform anywhere in Racine, Kenosha, or Walworth County, contact us for a free, confidential consultation. Call or text 24/7 at (262) 632-5000. We have defended Wisconsin criminal cases continuously since 1994.

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