Semien et al v. PubMatic Inc.
Summary
Plaintiffs allege that PubMatic’s tracking technologies collected browsing information across websites and compiled detailed profiles without their consent. The January 27, 2026 order denied dismissal of the privacy and statutory interception claims while dismissing unjust enrichment with leave to amend; the source reflects ongoing litigation rather than a final liability determination. ([app.midpage.ai](https://app.midpage.ai/document/semien-v-pubmatic-inc--e2c444d4-a31f-41d8-9642-833581b0ac16))
Litigation Status
Procedural Posture
Putative class action; ruling on PubMatic’s Rule 12(b)(1) and 12(b)(6) motion addressing the first amended complaint. Amendment of Count IV was permitted by February 5, 2026. ([app.midpage.ai](https://app.midpage.ai/document/semien-v-pubmatic-inc--e2c444d4-a31f-41d8-9642-833581b0ac16))
Reported Holding
The court allowed the privacy and interception claims to proceed but dismissed unjust enrichment with leave to amend. ([app.midpage.ai](https://app.midpage.ai/document/semien-v-pubmatic-inc--e2c444d4-a31f-41d8-9642-833581b0ac16))
What the Court Decided
Plaintiffs adequately pleaded Article III standing, intrusion upon seclusion, CIPA interception and aiding-and-abetting claims, an ECPA claim, and a CIPA pen-register claim. Unjust enrichment lacked allegations that legal remedies were inadequate. ([app.midpage.ai](https://app.midpage.ai/document/semien-v-pubmatic-inc--e2c444d4-a31f-41d8-9642-833581b0ac16))
What the Court Did Not Decide
The court did not determine ultimate liability, resolve disputed consent, or establish whether PubMatic actually intercepted communications in transit. ([app.midpage.ai](https://app.midpage.ai/document/semien-v-pubmatic-inc--e2c444d4-a31f-41d8-9642-833581b0ac16))
Significance
Generally viewed as plaintiff-favorable. Characterizations of significance describe how the matter has generally been discussed in tracked public sources; individual holdings are often narrow, procedural, or fact-specific, and this page does not state or imply broader holdings than the sources support.
What This Page Does and Does Not Say
This page reports what our tracked public sources say about this matter — including, where identified, the procedural posture (for example, a ruling on a motion to dismiss is not a final merits decision). It does not report legal conclusions beyond those sources, does not predict outcomes, and does not constitute legal advice.
Technologies at Issue
- pixel tracking (PubMatic pixel)
- real-time bidding (RTB)
- identity resolution / Identity Hub
- pixel tracking
- identity hub / identity resolution
- partner pixels / third-party tracking
- web adtech pixels
- PubMatic pixel
- Real-time bidding
- Identity Hub
- Cookie identifier syncing
- Browser and device fingerprinting
- Full-string URL collection
- Cross-site profiling
Third parties named or identified in tracked sources: PubMatic Inc., Mindbloom, Peacock, Zillow, Bon Appetit, Mindbloom (referenced), Publisher clients (examples in complaint: Peacock, Zillow, Bon Appetit).
Statutes Invoked
- Cal. Penal Code §§ 631(a), 638.51(a); 18 U.S.C. § 2511
- Cal. Penal Code §§ 631(a), 638.51(a); 18 U.S.C. § 2511; Cal. Civ. Code § 1798.99.80(c)
- California Penal Code §§ 631(a), 638.51(a); Electronic Communications Privacy Act, 18 U.S.C. § 2511
Claims Asserted
- Intrusion upon seclusion (California common law)
- California Penal Code § 631(a) (CIPA § 631)
- California Penal Code § 638.51(a) (CIPA § 638.51)
- Electronic Communications Privacy Act (ECPA), 18 U.S.C. § 2511
- Unjust enrichment
- California Penal Code § 631(a)
- California Penal Code § 638.51(a) (pen register claim)
- Electronic Communications Privacy Act (18 U.S.C. § 2511)
- Intrusion upon seclusion
- CIPA § 631(a) interception, use, and aiding-and-abetting claims
- CIPA § 638.51(a) pen-register claim
- ECPA § 2511 interception claim
What This Matter May Mean for Website Operators
For operators using similar technologies, the recurring factual questions in matters like this one are whether advertising pixels transmit page URLs or hashed form data before a consent choice. Our scanner tests these behaviors empirically.
Because this matter is pending, anything reported here is procedural — allegations and interim rulings, not final determinations.
Detection of a similar technology on a website is an informational risk indicator, not a legal conclusion, and nothing in this section is legal advice.
Related Intelligence
Sources
- Semien v. PubMatic Inc., 3:25-cv-03164
- Semien et al v. PubMatic Inc., No. 3:2025cv03164 - Document 47 (N.D. Cal. 2026)
- Semien et al v. PubMatic Inc., No. 3:2025cv03164 - Document 47 (N.D. Cal. 2026)
About This Page
Publisher: Inspection-Ready Institute, Inc. (DBA Crandall Consulting), an independent website compliance and risk consultancy. We are not a law firm and nothing on this page is legal advice.
How this content is produced: Facts are extracted from publicly available sources — court and government materials, recognized legal press, professional analysis, and industry reports — by our litigation intelligence engine, stored with full source provenance, and rendered from the database. Risk guidelines are computed by a deterministic formula, never by an AI model directly. See the full methodology.
Limitations: Counts labeled "Tracked" reflect matters identified in our source set and are not official court statistics. We report what courts decided and did not decide; we do not predict outcomes.
Corrections: If you believe anything on this page is inaccurate, contact us via the contact page and we will review the underlying sources promptly.
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