In 2020, Sonos sued Google in the N.D. of California, asserting two “zone scenes”  wireless speaker patents (US 10,848,885 and 10,469,966) that allow for overlapping groups of speakers. A jury found Google liable and awarded $30 million in damages. In an unusual move, District Judge William Alsup threw out the verdict in a 55-page post-trial order. He held the patents unenforceable for prosecution laches and invalid for lack of written description support. Judge Alsup found Sonos had engaged in a “daisy chain” continuation strategy to keep the patent family alive for over 13 years.  Although longer than average, this timeline is not long for a patent family recognized as valuable.  But, one quirk is that the particular “overlapping zone scene” claims  were not presented in claim form until 2019. And, they were added after Google began selling products with that feature. Judge Alsup also concluded that Sonos’s 2019 amendments were directed to new matter not supported by the original 2006–2007 applications -- i.e., lacking written description suport.  Without that priority claim, those earlier filings became anticipatory prior art to the later would-be continuation.

The appeal is now pending, and the Federal Circuit held oral arguments on July 10, 2025.  The case raises fundamental questions about the scope of the "sparingly applied" doctrine of prosecution laches and also about the proper procedure for raising written description/anticipation issues during trial.

• Listen to Oral Args; Rough Transcript.
• Dennis Crouch, Prosecution Laches from Woodbridge to Sonos: A 170-Year Journey, Patently-O (June 21, 2025),
• Dennis Crouch, Google v. Sonos: Oral Arguments, Patently-O (July 11, 2025),
• Dennis Crouch, Preview: Federal Circuit Oral Argument in Google v. Sonos (July 10, 2025), Patently-O (June 30, 2025),
• Dennis Crouch, Redefining Patent Continuation Strategy: Sonos v. Google Appeal, Patently-O (Feb. 13, 2024),
• Dennis Crouch, Federal Circuit Affirms ITC Divided Opinion in Sonos v. ITC, Patently-O (Apr. 9, 2024),
• Dennis Crouch, Sonos v. Google: Late Claiming Estoppel, Patently-O (Dec. 8, 2023).

I believe that a typical Federal Circuit panel would side with the appellant Sonos. But, the panel in this case is somewhat unique. The combination of Judges Prost and Lourie creates an interesting dynamic given their opposing positions in the 2010 prosecution laches case of Cancer Research. Judge Prost's dissent in that case shows her willingness to apply prosecution laches.  Although Judge Lourie did not find laches in Cancer Research, he is Judge Lourie authorship of Symbol v. Lemelson—the decision that revived prosecution laches in 2005.

In ratings of "patent friendliness" (including one by Google's attorney Dan Bagatel), Judges Prost and Lourie are among the three least patent-friendly judges on the Federal Circuit.  Judge Bumb, sitting by designation from the District of New Jersey, adds unpredictability as she lacks the extensive patent law track record of her colleagues. All three are Republican appointees who generally embrace textualist approaches, but that judicial philosophy matters less here since prosecution laches is an entirely judge-made equitable doctrine with minimal congressional guidance beyond Section 282's broad authorization of equitable defenses.

by Dennis Crouch

The Federal Circuit is now confronting a second major mandamus petition challenging the USPTO's major changes with regard to its approach to discretionary denials in inter partes review proceedings. In re Motorola Solutions, Inc., No. 25-134 (Fed. Cir. 2025).  Motorola presents an even more procedurally compelling challenge to Acting Director Stewart's retroactive system changes than the earlier In re SAP petition I discussed previously. While both cases attack the same underlying agency action, Motorola's petition benefits from having actually obtained PTAB institution decisions before they were subsequently vacated, creating a more concrete harm from the retroactive policy change.

• In re_ Motorola Solutions, Inc. - mandamus petition
• In re_ Motorola Solutions, Inc. - Unified amicus
• In re_ Motorola Solutions, Inc. - CCIA amicus
• In re_ Motorola Solutions, Inc. - US*MADE amicus

• Dennis Crouch, SAP’s Mandamus Petition Challenging Trump Admin's Discretionary Denial Policy Shift, Patently-O (July 10, 2025).

Responsive briefs are due July 14 in SAP and July 21 in Motorola.

Today the Federal Circuit is hearing oral arguments in Google v. Sonos on the doctrine of prosecution laches. The panel is interesting and has the potential of resulting in a pro-Google decision.  Federal Circuit Judges Prost and Lourie, along with  D.N.J. District Court Judge Renée Marie Bumb, sitting by designation.

Judge Lourie authored the Symbol v. Lemleson decision that revived the doctrine back in 2005. More interestingly, Judge Lourie wrote the opinion in Cancer Research Tech. Ltd. v. Barr Laboratories, Inc., 625 F.3d 724 (Fed. Cir. 2010), with Judge Prost in dissent. In that case, the majority found no laches, but Judge Prost would have found the patent unenforceable due to prosecution laches.

by Dennis Crouch

Egenera, Inc. v. Cisco Sys., Inc., No. 2023-1428, slip op. (Fed. Cir. July 7, 2025)

During claim construction proceedings, The patentee Egenera and defendant Cisco disputed several claim terms including "computer processor/processor" and aspects of "emulate Ethernet functionality over the internal communication network". However, "neither party asked the district court to determine what the patent specifically means by 'emulate Ethernet functionality,'" content to leave this key term to its "plain and ordinary meaning."  This strategic choice ultimately proved fatal when the case reached summary judgment. The district court found that Cisco's CPUs "used" Ethernet functionality but found no evidence of emulation, concluding that "use of a communications network is not emulation of the functionality of that network." 

by Dennis Crouch

The pending Radian Memory case could fundamentally reshape patent litigation.  This is a follow-on article about the preliminary injunction motion in Radian Memory v. Samsung pending before Judge Gilstrap in the Eastern District of Texas. The patentee-plaintiff is a non-practicing entity -- but still argues that it has a right to injunctive relief based upon traditional equitable principles, even under the requirements of eBay. In June, the DOJ and USPTO filed a statement of interest in the case supporting the availability of injunctive relief as pro-competitive. Both sides have now provided additional arguments with a July 16 evidentiary hearing scheduled. Radian particularly argues that the recent Supreme Court cases of Trump v. CASA, Inc., 24A884, 602 U.S. ___ (June 27, 2025) and Mahmoud v. Taylor, 24-297, 602 U.S. ___ (June 27, 2025), reaffirm that the key source of law should be founding-era equity practices. The key sticking point for NPE injunctive relief is irreparable harm -- and Radian's point is that the founding era cases are clear that ongoing infringement of a property right inherently causes irreparable harm.

• See, Dennis Crouch, U.S. Government: NPEs Deserve Injunctive Relief when their Patents Are Infringed, Patently-O (June 26, 2025).
• RADIAN'S RESPONSE TO THE UNITED STATES’ STATEMENT OF INTEREST
• RADIAN's NOTICE OF SUPPLEMENTAL AUTHORITY 
• SAMSUNG’S RESPONSE TO THE UNITED STATES’ STATEMENT OF INTEREST

Radian’s argument has some legs -- and would be a major transformation if successful.  Almost certainly, the “principles of equity” in 35 U.S.C. § 283 incorporate the historical practices of English Chancery and the Founding era.  Although eBay has been read as eliminating any presumption of irreparable harm due to ongoing infringement, that result is only implied by the case. eBay itself made historical errors that make it difficult to know whether the court intended to apply a straight historical analysis, or one that is more fictionalized.

by Dennis Crouch

Acting Director Coke Morgan Stewart has been incredibly active in reshaping the PTAB's approach to IPR discretionary denials.  This post focuses on her newly implemented "settled expectations" doctrine that treats patent age as a primary factor for denying institution. This new framework was formalized in the March 26, 2025 "Interim Process for PTAB Workload Management" memorandum and subsequently applied in a series of Director Discretionary Denial decisions in June 2025. The doctrine creates a temporal shield for older patents and calls forth some interesting parallels to existing doctrine, including laches and trademark incontestability.

by Dennis Crouch

This post digs into the pending mandamus action In re SAP.  In the case, SAP raises a constitutional challenge to Director Stewart's aggressive discretionary denial approach -- as a violation of both due process and separation of powers.

• IPR2024-01495 Decision Denying Institution
• IPR2024-01495, -01496 Director Review Decision
• SAP - Mandamus Petition

The IPR statute provides the USPTO Director virtually unreviewable authority to grant or deny inter partes review (IPR) petitions. As part of the initial implementation of the IPR system, then USPTO Director Dave Kappos delegated authority to the PTAB to make those determinations. But, Acting Director Coke Morgan Stewart has substantially shifted the practice in recent months by substantially expanding the scope of discretionary institution denials -- these are refusals to institute IPRs even when the petition raises a substantial enough  patentability challenge.  Under Director Vidal, one important approach avoid discretionary denial was the Sotera safe harbor, stemming from Sotera Wireless, Inc. v. Masimo Corp.. In Sotera, the petitioner stipulated that it would not pursue in the parallel litigation any invalidity ground that it could raise in the IPR, thus eliminating most potential overlap in issues between the IPR and any parallel litigation. This broad stipulation (often called a “Sotera stipulation”) became a de facto safe harbor that was then formally embraced by a 2022 memorandum by Director Kathi Vidal.  That memo clearly stated that the the Board would not discretionarily deny institution” in two key situations: (1) when the petitioner agreed to a broad Sotera stipulation (foregoing any invalidity arguments in court that could have been raised in the IPR), despite ongoing parallel litigation, or (2) when the petition presented a “compelling” unpatentability challenge.  This interim guidance operated as binding agency internal policy that curbed Fintiv denials and reassured petitioners that certain bright-line safe harbors would be respected. The result was a substantial decrease in discretionary denials.

Fast forward to 2025 and dramatic policy changes by Acting Director Coke Morgan Stewart substantially increasing discretionary denials.  In particular, Stewart rescinded the June 2022 Vidal memo and ultimately reinstated the broader pre-2022 Fintiv framework.  A Sotero stipulation is no longer sufficient to avoid discretionary denials, and Director Stewart has more recently expanded the justifications for discretionary denials, including "settled expectations" where the patent issued 7+ years ago and was not challenged during that interim.

Importantly for SAP, this policy change was applied immediately and retroactively to pending cases. In other words, IPR petitions filed while the Vidal Memo was in effect could still be decided under the new more expansive discretionary denial regime, as long as the PTAB had not yet instituted by the time of the rescission. This is precisely what happened to SAP.

by Dennis Crouch

Judge Alsup issued his controversial unenforceability decision in Sonos v. Google back in October 2023, and the appeal has been pending since then.  The Federal Circuit recent scheduled arguments for July 10, 2025.  I wanted to offer a bit of a preview of these upcoming oral arguments.

In 2020, Sonos sued Google for infringing its “zone scenes” patents, which cover techniques for grouping networked speakers into saved scenes (including overlapping groups of speakers). U.S. Patent Nos. 10,848,885 and 10,469,966.  A jury found Google liable and awarded $30 million in damages.  N.D.Cal. Judge William Alsup then took the unusual step of throwing out the verdict. Ruling on post-trial motions, Judge Alsup found the two patents unenforceable due to prosecution laches and invalid for lack of written description support. Sonos promptly appealed, and it is that appeal that is now pending.

Judge Alsup’s Decision: In his 55-page order, Judge Alsup found that Sonos had engaged in a “daisy chain” continuation strategy to keep its patent family alive for over 13 years. Sonos filed an initial provisional application in 2006, but did not present the asserted overlapping-scene claims for examination until 2019.  By then, Google and others had already developed and sold products implementing the overlapping-zone technology.

by Dennis Crouch

I learned of this significant development from Michael Shapiro's Bloomberg article reporting that the U.S. government took the unusual step of filing a statement of interest in a district court patent case, urging consideration of preliminary injunctive relief for a non-practicing entity (NPE). Radian Memory Systems LLC v. Samsung Electronics Co., No. 2:24-cv-1073 (E.D. Tex. 2025). The June 24, 2025 filing represents a notable intervention by both the Department of Justice Antitrust Division and the U.S. Patent and Trademark Office in what is part of its "America First Antitrust Enforcement" efforts.

Read the documents:

by Dennis Crouch

The USPTO has begun implementing a comprehensive enforcement system for false assertions of small entity and micro entity fee status. This is continuation of a process began under Director Vidal and implementation of statutory changes in 2023.  See Statutory Penalties for False Assertions or Certifications of Small and Micro Entity Status (June 2025).  The memo explains a notice-and-order process that removes applications from examination pending resolution and can result in significant financial penalties, examination delays, and patent term adjustment reductions for applicants who improperly claim small or micro entity status.

2023 legislation added a penalty provisions to 35 U.S.C. § 41(j) for small entity violations and § 123(f) for micro entity violations. A subsequent December 2024 amendment added explicit good faith exceptions to both penalty provisions.  The statute provides for a penalty of "not less than 3 times the amount that the entity failed to pay as a result of the false certification" and does not provide a timeline for enforcement - noting that the fine applies "whether the Director discovers the false certification before or after the date on which a patent has been issued."