Untitled case

An Inter Partes Review (IPR) case, IPR2025-00255, has been initiated by Unified Patents against the owner of U.S. Patent No. 9,633,139. Unified Patents is a member-based organization focused on deterring frivolous patent litigation by Non-Practicing Entities (NPEs), often referred to as patent trolls, by challenging the validity of their patents through post-grant proceedings like IPRs. While the specific patent owner for IPR2025-00255 could not be definitively identified through public search results at this time, Unified Patents' operational model strongly suggests the patent owner is an NPE.

The patent at issue, U.S. Patent No. 9,633,139, is titled "Methods and systems for search indexing." The patent's abstract describes a system designed for quick and efficient searching. It includes instructions to read multiple search strings entered into a single search field and incrementally filter results to find documents where words begin with the entered strings. This broadly covers technology related to incremental or "reactive" search, where search results are refined as a user types characters.

The case is currently pending before the Patent Trial and Appeal Board (PTAB) and has been instituted for review. The PTAB is a specialized administrative body within the U.S. Patent and Trademark Office (USPTO) that offers a typically faster and more cost-effective alternative to district court litigation for challenging patent validity, often with a lower burden of proof for invalidity. The procedural posture of an IPR at the PTAB is notable for its role in patent validity challenges, especially given recent emphasis on discretionary denial factors such as "settled expectations" of patent owners and the timing of parallel district court proceedings. Unified Patents' strategy of using IPRs to target patents asserted by NPEs has a significant impact on the patent landscape, aiming to reduce the volume of what it considers low-quality patent assertions across various technology sectors.

For the Inter Partes Review (IPR) case IPR2025-00255, challenging US Patent 9,633,139, the primary legal development is the IPR itself, which has been instituted and is currently pending. However, the specific Patent Owner and details regarding any associated patent infringement litigation are not explicitly available in the provided search results.

Here is a summary of the known legal developments and current posture:

Parallel PTAB IPR Proceedings (IPR2025-00255)

• Petitioner: Unified Patents. The IPR was initiated by Unified Patents, an organization known for challenging patents, particularly those asserted by Non-Practicing Entities (NPEs).
• Patent at Issue: U.S. Patent 9,633,139.
• Status: Instituted - Pending. The Patent Trial and Appeal Board (PTAB) has decided to review the patentability of the challenged claims.
• Procedural Developments: An "Order: ORDER Denying Authorization to File Motion to Terminate" was filed on March 19, 2026, indicating that the IPR is actively proceeding. On the same date, a "Patent Owner's Response" was also filed.
• Technology Center: The Patent Owner/Respondent Technology Center for this IPR is 2100, which pertains to Computer Architecture, Software, and Information Security.
• Patent Owner and Dates: The identity of the Patent Owner for IPR2025-00255, as well as the specific filing date and institution date for this IPR, could not be definitively identified from the publicly available search results.

Patent Infringement Litigation

• No Identified Litigation: Despite thorough searches, no specific patent infringement litigation asserting U.S. Patent 9,633,139 was identified in the provided search results. Unified Patents typically initiates IPRs against patents that are being asserted in district court litigation. Without the Patent Owner's name, it is not possible to conclusively identify any related lawsuits.

Conclusion

IPR2025-00255 is an active Inter Partes Review challenging US Patent 9,633,139, initiated by Unified Patents and currently in the "Instituted - Pending" phase. While procedural documents such as an order denying a motion to terminate and a Patent Owner's response have been filed, the specific identity of the Patent Owner and details of any underlying patent infringement litigation could not be determined from the available information.

Unified Patents, the petitioner in IPR2025-00255, typically utilizes a combination of in-house counsel and, at times, outside law firms for its challenges before the Patent Trial and Appeal Board (PTAB). However, the specific counsel of record for IPR2025-00255 has not been explicitly identified in publicly available search results.

Based on Unified Patents' general practice in PTAB proceedings, their legal team frequently includes:

• Jonathan Stroud
  • Role: Chief IP Counsel
  • Firm: Unified Patents Inc. (Washington, D.C.)
  • Experience: Stroud serves as Chief IP Counsel for Unified Patents and has been listed as in-house counsel in PTAB filings.
• Roshan Mansinghani
  • Role: Legal Head - NPE / Head of Operations
  • Firm: Unified Patents Inc. (Washington, D.C.)
  • Experience: Mansinghani is involved in legal strategy and operations for Unified Patents and has appeared as in-house counsel in PTAB proceedings.
• Jordan Rossen
  • Role: Senior Patent Counsel
  • Firm: Unified Patents Inc. (Washington, D.C. or remote)
  • Experience: Prior to joining Unified Patents, Rossen practiced in the intellectual property litigation departments at Ropes & Gray and Paul Hastings for eleven years, representing clients before the PTAB, International Trade Commission, district courts, and Federal Circuit across various industries.
• Michelle Callaghan (Aspen)
  • Role: Senior Patent Counsel
  • Firm: Unified Patents Inc. (Washington, D.C. or remote)
  • Experience: Callaghan (also referred to as Aspen) prepares and litigates post-grant proceedings before the PTAB for Unified Patents. She previously practiced at Erise IP, defending clients and challenging patents before the PTAB.
• David Seastrunk
  • Role: Senior Patent Counsel
  • Firm: Unified Patents Inc. (Washington, D.C. or remote)
  • Experience: Seastrunk prepares and litigates post-grant proceedings for Unified Patents. He previously practiced at Finnegan, Henderson, Farabow, Garrett & Dunner, LLP, where he was involved in post-grant proceedings, district court cases, and International Trade Commission investigations.
• Ellyar Barazesh
  • Role: Senior Patent Counsel
  • Firm: Unified Patents Inc. (Washington, D.C. or remote)
  • Experience: Barazesh has been a speaker for Unified Patents on strategies for filing ex parte reexaminations, indicating involvement in PTAB-related matters.
• Kelly Hughes
  • Role: Senior Patent Counsel
  • Firm: Unified Patents Inc. (Washington, D.C. or remote)
  • Experience: Hughes is listed as a Senior Patent Counsel on Unified Patents' team page, suggesting involvement in their patent challenge activities.

Unified Patents has also engaged outside counsel for PTAB proceedings in other cases. For example, in IPR2019-00670, Brian W. Oaks of Baker Botts, L.L.P. (Austin, TX) was listed as counsel. In an ex parte reexamination, Stephen Cortiaus and Ava Chung of Slater Matsil represented Unified Patents.

However, without specific docket information for IPR2025-00255, it is not possible to definitively identify the lead counsel or any specific outside counsel retained for this particular case. Filings for PTAB proceedings are typically public through the USPTO's Patent Trial and Appeal Board End-to-End (PTAB E2E) system.

I'll research the Patent Owner's counsel in this IPR (the "defendant" equivalent in a PTAB proceeding).

Key finding: the search results contradict the case metadata on the petitioner. Let me dig deeper.

Now let me verify counsel details and identify Microsoft's defense counsel in the parallel district court case.

Threshold point: the "defendant" mapping — and a metadata conflict

Two things must be said up front, because they change who counts as "defendant" here.

1. This is a PTAB proceeding, not a district court case. In an IPR there is no plaintiff/defendant; the party defending the patent is the Patent Owner (the respondent), and the petitioner is the challenger. There is also no "local counsel" role at the PTAB — that concept only exists in the parallel district court litigation. I therefore report (a) the Patent Owner's counsel of record in IPR2025-00255, and (b) the actual defendant in the underlying infringement suit and its counsel.

2. The case metadata conflicts with the public record — flagging explicitly. The prompt (and the earlier "Case overview" / "Plaintiff representatives" sections) identifies the petitioner as Unified Patents. Every primary document I found shows the petitioner is Microsoft Corporation, and the Patent Owner is X1 Discovery, Inc.:

• Microsoft Corporation v. X1 Discovery, Inc., IPR2025-00255 (Patent 9,633,139 B2); companion petitions IPR2025-00253 ('035 patent) and IPR2025-00254 ('490 patent).
• Director's discretionary-denial decision, Paper 13 (June 25, 2025), captioned "MICROSOFT CORPORATION, Petitioner, v. X1 DISCOVERY, INC., Patent Owner," covering IPR2025-00253/-00254/-00255.
• X1's Updated Mandatory Notices (e.g., IPR2025-00254, Paper 29, Feb. 13, 2026) identify only X1 Discovery, Inc. as real party-in-interest on the Patent Owner side.

Per the operating rules I treat the metadata as authoritative for party names, but the docket record is unambiguous and the earlier "Unified Patents" attribution appears to be an error (Unified's name appears in the search results only because its litigation database hosts the C.D. Cal. docket). I flag this rather than silently overwrite it.

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Patent Owner's counsel of record — X1 Discovery, Inc. (the respondent/"defendant" side in the IPR)

Goodwin Procter LLP represents X1 Discovery, Inc. in the IPR family. Per X1's Updated Mandatory Notices under 37 C.F.R. § 42.8(b)(3):

Service in the IPR family is directed to DG-X1-IPR@goodwinlaw.com (consent to electronic service under § 42.8(b)(4)). Correspondence in the related Director Review filings is copied to Gordon, Daughtrey and Larochelle at goodwinlaw.com.

No in-house counsel for X1 appears on the PTAB notices; Goodwin is acting as outside counsel for both the IPRs and the district court litigation.

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The actual infringement case and its defendant

X1's mandatory notices identify the underlying litigation as:

• X1 Discovery, Inc. v. Microsoft Corp., No. 8:23-cv-02415-GW-JDE (C.D. Cal.), filed December 19, 2023 — asserting the '035, '139 and '490 patents (plus '977 patent per the updated notice) against Microsoft.
• Related: X1 Discovery, Inc. v. Acer Inc., No. 2:23-cv-10674 (C.D. Cal.); X1 Discovery, Inc. v. ASUSTeK Computer Inc., No. 2:23-cv-10672 (C.D. Cal.); X1 Discovery, Inc. v. Dell Technologies Inc., No. 2:24-cv-04109 (C.D. Cal.); and ITC Inv. No. 337-TA-1389, Certain Computing Devices Utilizing Indexed Search Systems & Components Thereof, terminated April 28, 2025 (ITC found no violation based on prosecution disclaimer from the '139 patent).

In that infringement case the defendant is Microsoft Corporation, and the plaintiff (X1) is represented by Goodwin — Natasha Daughtrey appeared on the complaint.

Microsoft's defense counsel is not confirmed from the sources I could reach. What I can say with sourcing limits:

• A certificate/service artifact in the IPR family references a Klarquist Sparkman LLP service address, "Msft-X1-IPRs@klarquist.com," with Samuel Thacker (Klarquist) on the correspondence, and a third-party aggregator lists Andrew M. Mason (Klarquist Sparkman LLP) as an attorney associated with IPR2025-00255 (petition filed 12/20/2024). This suggests Klarquist Sparkman is Petitioner Microsoft's PTAB counsel, but I could not verify that against a filed power of attorney or appearance, and I found no confirmed C.D. Cal. defense-side firm for Microsoft.
• I did not reach PACER or the C.D. Cal. docket sheet for 8:23-cv-02415 in this research pass, so I cannot state Microsoft's district court counsel. Treat the Klarquist attribution as unverified.

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Caveats and confidence

• High confidence: Patent Owner = X1 Discovery, Inc.; lead counsel = Lori A. Gordon (Goodwin Procter, Washington, D.C.); back-up counsel Larochelle (Boston) and Daughtrey (L.A., pro hac vice); Dutta listed as back-up but subject to a pending unopposed withdrawal motion. These come from X1's own § 42.8(b)(3) disclosures and signed filings.
• Moderate confidence: the withdrawal actually being granted in -00255 (the motion text I retrieved is from IPR2025-00254); the appeal notices (Fed. Cir. 26-2177 from the '035 IPR, and 26-2179 reportedly from IPR2025-00255, filed 8/20/2026) come from a third-party aggregator, not the Federal Circuit docket. If 26-2179 is real, a final written decision has issued in IPR2025-00255 and the "Instituted – Pending" status in the metadata is stale. Verify this before relying on it.
• Low confidence / unverified: Microsoft's counsel (Klarquist Sparkman hypothesis); counsel for the Acer/ASUS/Dell defendants and ITC respondents (commentary on the ITC decision lists Adam R. Hess, Ronald S. Lemieux and Woli I. Urbe, but I could not verify their firm or which respondents they represented, so I decline to name firms).
• Not contradicted but worth noting: the earlier section's counsel list for "Plaintiff representatives" (Stroud, Mansinghani, Rossen, Callaghan, Seastrunk, Barazesh, Hughes of Unified Patents; Oaks of Baker Botts) has no apparent application to this docket, since Microsoft — not Unified Patents — is the petitioner.

Suggested next verification steps: USPTO PTAB E2E / PTAB Center page for IPR2025-00255 (Papers 1, 3, 10, 29, and any withdrawal order) for the operative § 42.8(b)(3) counsel list; PACER docket for 8:23-cv-02415-GW-JDE for defense-side appearances; and the Federal Circuit docket for 26-2179 to confirm the appellate posture.