Untitled case

This patent infringement litigation, case number 2:20-cv-00851, is venued in the United States District Court for the Western District of Washington, presided over by Senior Judge Thomas S. Zilly. The plaintiff is International Business Machines Corporation (IBM), a global technology and consulting company. The defendants are Zillow Group, Inc. and Zillow, Inc., well-known online real estate marketplaces.

The core of the dispute in this specific case (2:20-cv-00851) involved IBM accusing Zillow of infringing multiple patents related to graphical display technology, though the provided prompt focuses on US Patent 7,631,346. US Patent 7,631,346, titled "Method and system for a runtime user account creation operation within a single-sign-on process in a federated computing environment," generally describes a method and system for dynamically creating user accounts during a single sign-on (SSO) process within a federated computing environment. This technology is relevant to how large platforms manage identity across distributed services, enabling a service provider to provision a user account the first time a federated identity assertion is received, without requiring pre-registration. While the initial complaint in 2:20-cv-00851 asserted several patents, Zillow successfully obtained a dismissal of six out of seven asserted patents, with the seventh stayed pending appeal of partial invalidation in an Inter Partes Review (IPR).

The case is notable for its significant procedural developments, particularly concerning the patent eligibility of US Patent 7,631,346. IBM appealed a lower tribunal's finding that this patent was unpatentable under 35 U.S.C. § 101, a challenge that reached the Federal Circuit. On December 9, 2025, the Federal Circuit affirmed the lower court's unpatentability finding, effectively extinguishing IBM's ability to enforce this specific patent against Zillow. This outcome signifies a major win for Zillow and has implications for the broader technology sector, particularly for companies operating in cloud identity platforms, enterprise software, and e-commerce authentication that rely on federated identity architectures. The Federal Circuit's affirmance against IBM, a company with a substantial identity and access management patent portfolio, highlights the ongoing scrutiny of software-related patents under Section 101.

Key Legal Developments and Outcome for International Business Machines Corporation v. Zillow Group, Inc. et al. (2:20-cv-00851)

This patent infringement litigation, filed in the Washington Western District Court, primarily involved U.S. Patent No. 7,631,346 (the '346 patent), among others. The case has seen significant developments, culminating in a Federal Circuit decision affirming the unpatentability of the '346 patent.

Chronological Developments:

• Filing & Initial Pleadings (2020-05-28): International Business Machines Corporation (IBM) initiated the lawsuit against Zillow Group, Inc. and Zillow, Inc. in the U.S. District Court for the Western District of Washington, assigned case number 2:20-cv-00851. The complaint asserted infringement of multiple patents, including US7631346B2.
• Pre-trial Motions & Dismissals (2022): In 2022, Zillow successfully moved to dismiss six of the seven asserted patents in case 2:20-cv-00851. The litigation concerning the seventh patent was stayed, pending the outcome of an appeal related to its partial invalidation in an Inter Partes Review (IPR).
• Claim Construction (Markman) (2022-10-28): The Western District of Washington court engaged in claim construction for the case. A notable point of contention involved the interpretation of terms such as "a/said/the computer processor" and whether they should be construed to mean "one or more processors." The court issued an order regarding claim construction on October 28, 2022.
• Federal Circuit Appeal (2021-2350, 2022-10-17): On October 17, 2022, the U.S. Court of Appeals for the Federal Circuit issued an opinion in International Business Machines Corp. v. Zillow Group, Inc., Case No. 2021-2350, which was an appeal stemming from the Western District of Washington case 2:20-cv-00851-TSZ. This opinion addressed issues of patent eligibility under 35 U.S.C. § 101 for claims 9 and 13.
• Parallel PTAB IPRs (Earlier for '346 patent): Prior to this specific district court litigation, U.S. Patent 7,631,346B2 was subjected to Inter Partes Reviews (IPR2016-00609 and IPR2016-00608) initiated by Kayak Software Corp., Opentable, Inc., and Priceline.com in 2016.
• Federal Circuit Appeal (24-1274, Zillow v. IBM, 2023-12-21 to 2025-12-09): On December 21, 2023, Zillow, Inc. filed an appeal (No. 24-1274) with the Federal Circuit to challenge the patentability of IBM's US7631346B2. This appeal sought to overturn a "lower tribunal's determination that the patent claims are unpatentable" for US7631346B2. On December 9, 2025, the Federal Circuit affirmed the finding that the claims of US7631346B2 are unpatentable. This outcome effectively extinguished IBM's ability to enforce the '346 patent against Zillow.
• Related Federal Circuit Appeal (24-1238, Ebates v. IBM, 2023-12-07 to 2024-06-25): Another appeal concerning US7631346B2 was filed by Ebates Performance Marketing, Inc. against IBM (Appeal No. 24-1238) on December 7, 2023. This appeal was dismissed on June 25, 2024, following Ebates's motion to withdraw as a party, and therefore, no merits ruling on the patent's validity was issued in this particular proceeding.
• Final Disposition for '346 patent: The Federal Circuit's decision on December 9, 2025, affirming the unpatentability of US7631346B2 in the appeal brought by Zillow (24-1274), represents the final disposition for this specific patent in the context of this litigation. The case 2:20-cv-00851 is currently listed as "open" on Unified Patents, suggesting other aspects or patents from the original complaint might still be active. However, for patent 7,631,346, the Federal Circuit's ruling means it is unpatentable and cannot be enforced by IBM against Zillow.

In the patent infringement case International Business Machines Corporation v. Zillow Group, Inc., Case No. 2:20-cv-00851 in the Washington Western District Court, International Business Machines Corporation (IBM) is the plaintiff. The counsel of record representing IBM in this matter, particularly noted during the Federal Circuit appeal (Case No. 21-2350), includes attorneys from Desmarais LLP.

The following attorneys from Desmarais LLP represented IBM as plaintiff-appellant in the Federal Circuit appeal stemming from this case:

• Goutam Patnaik

  • Role: Argued for plaintiff-appellant (IBM). Likely lead counsel.
  • Firm: Desmarais LLP, Washington, DC office.
  • Experience Note: Mr. Patnaik is a partner at Desmarais LLP and focuses on patent litigation, with experience representing clients in federal district courts and the Federal Circuit. He is noted for arguing for IBM in this particular appeal.

• John M. Desmarais

  • Role: Represented plaintiff-appellant (IBM). Likely lead counsel.
  • Firm: Desmarais LLP, New York, NY office.
  • Experience Note: Mr. Desmarais is the founding partner of Desmarais LLP and is a highly prominent patent litigator known for representing major technology companies in high-stakes patent disputes.

• William Findlay

  • Role: Represented plaintiff-appellant (IBM).
  • Firm: Desmarais LLP, New York, NY office.
  • Experience Note: Mr. Findlay is a partner at Desmarais LLP with experience in patent litigation, having represented IBM in this Federal Circuit appeal.

• Karim Zeddam Oussayef

  • Role: Represented plaintiff-appellant (IBM).
  • Firm: Desmarais LLP, New York, NY office.
  • Experience Note: Mr. Oussayef is an attorney at Desmarais LLP, involved in the representation of IBM in this patent appeal.

While not explicitly listed as "counsel of record" in a docket entry for this specific case, individuals like Manny Schecter (Chief Patent Counsel and Associate General Counsel) and Ken Corsello (IP Law Counsel) are key in-house intellectual property attorneys for IBM who oversee the company's patent litigation and strategy. They would likely be involved in managing the litigation for IBM, even if not formally appearing as external counsel of record.

I'll research the defense counsel of record for Zillow in this case.

I have strong primary-source data now. Let me verify a few remaining details: the identity/firm of the additional local counsel, current counsel status, and the later Federal Circuit appeal.

Now let me check the later proceedings (2023–2025) and the Federal Circuit appeal, to confirm whether defense counsel changed.

Counsel of Record for Defendants Zillow Group, Inc. and Zillow, Inc.

Headline finding: Zillow's defense has been handled throughout by Susman Godfrey L.L.P. — the same firm that represented Zillow in the pre-transfer Central District of California phase (No. 8:19-cv-01777), in the W.D. Wash. case after transfer, in the related case No. 2:20-cv-01130, and in both Federal Circuit appeals. No change of defense firm appears in any docket entry I could verify. There are no Zillow in-house attorneys appearing as counsel of record (unlike IBM, where in-house personnel were referenced in the earlier plaintiff section).

Susman Godfrey LLP — lead/merits counsel (Seattle and Houston)