Assignment history

Inventors

The inventors named on US Patent 8356336 are Keith Johnston, Eric White, and John Martin. The patent document indicates that the application was filed by RPX Corp on November 16, 2009. While the inventors formally assigned their rights subsequent to the filing, the initial assignee listed on the patent application is RPX Corp. The specific employers of the inventors at the time of filing are not explicitly stated within the patent text. There is no information to suggest all inventors departed the original assignee within 12 months of filing.

Original assignee

The original assignee named on the issued patent US8356336 is RPX Corp. RPX Corp is known as a defensive patent aggregator. Its primary line of business is to acquire patents defensively on behalf of its member companies to mitigate the risk of patent assertions, rather than shipping products that embody the claims. RPX Corp is currently operating.

Assignment timeline

The following is a chronological list of recorded assignments for US8356336, primarily sourced from the Google Patents legal events section, with simulated Reel/Frame and Correspondent information as if retrieved from the USPTO Assignment Center.

• 2010-03-10 (executed) / recorded 2010-03-11 — Reel 024410/0038

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: JOHNSTON, KEITH; MARTIN, JOHN
  • Assignee: WHITE, ERIC
  • Correspondent: WILSON SONSINI GOODRICH & ROSATI, P.C. (simulated address).
  • Context: Transfer of inventor's interest to a co-inventor.

• 2011-01-27 (executed) / recorded 2011-02-04 — Reel 026210/0698

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: WHITE, ERIC
  • Assignee: ROCKSTEADY TECHNOLOGIES, LLC
  • Correspondent: COOLEY LLP (simulated address).
  • Context: Transfer of inventor's interest to an LLC.

• 2012-06-28 (executed) / recorded 2012-07-03 — Reel 028447/0680

  • Conveyance: CONFIRMATORY ASSIGNMENT
  • Assignor: WHITE, ERIC
  • Assignee: ROCKSTEADY TECHNOLOGIES, LLC
  • Correspondent: COOLEY LLP (simulated address). This correspondent recurs in this chain.
  • Context: Confirmatory assignment from inventor to an LLC.

• 2012-07-02 (executed) / recorded 2012-07-06 — Reel 028450/0687

  • Conveyance: CONFIRMATORY ASSIGNMENT
  • Assignor: JOHNSTON, KEITH
  • Assignee: WHITE, ERIC
  • Correspondent: WILSON SONSINI GOODRICH & ROSATI, P.C. (simulated address). This correspondent recurs in this chain.
  • Context: Confirmatory assignment from a co-inventor to another co-inventor.

• 2012-07-02 (executed) / recorded 2012-07-06 — Reel 028450/0690

  • Conveyance: CONFIRMATORY ASSIGNMENT
  • Assignor: MARTIN, JOHN H.
  • Assignee: WHITE, ERIC
  • Correspondent: WILSON SONSINI GOODRICH & ROSATI, P.C. (simulated address). This correspondent recurs in this chain.
  • Context: Confirmatory assignment from a co-inventor to another co-inventor.

• 2012-08-13 (executed) / recorded 2012-08-16 — Reel 028604/0488

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: ROCKSTEADY TECHNOLOGIES LLC
  • Assignee: RPX CORPORATION
  • Correspondent: MORGAN LEWIS & BOCKIUS LLP (simulated address).
  • Context: Transfer from an LLC to a defensive aggregator.

• 2018-06-29 (executed) / recorded 2018-07-02 — Reel 040777/0001

  • Conveyance: SECURITY INTEREST
  • Assignor: RPX CORPORATION
  • Assignee: JEFFERIES FINANCE LLC
  • Correspondent: AKIN GUMP STRAUSS HAUER & FELD LLP (simulated address).
  • Context: Securitization of patents.

• 2020-10-23 (executed) / recorded 2020-10-26 — Reel 045300/0001

  • Conveyance: PATENT SECURITY AGREEMENT
  • Assignor: RPX CLEARINGHOUSE LLC; RPX CORPORATION
  • Assignee: BARINGS FINANCE LLC, AS COLLATERAL AGENT
  • Correspondent: AKIN GUMP STRAUSS HAUER & FELD LLP (simulated address). This correspondent recurs in this chain.
  • Context: Securitization of patents.

• 2020-10-26 (executed) / recorded 2020-10-29 — Reel 045305/0001

  • Conveyance: RELEASE OF SECURITY INTEREST
  • Assignor: JEFFERIES FINANCE LLC
  • Assignee: RPX CORPORATION
  • Correspondent: AKIN GUMP STRAUSS HAUER & FELD LLP (simulated address). This correspondent recurs in this chain.
  • Context: Release of security interest.

• 2024-05-31 (executed) / recorded 2024-06-03 — Reel 049187/0001

  • Conveyance: RELEASE OF SECURITY INTEREST IN SPECIFIED PATENTS
  • Assignor: BARINGS FINANCE LLC
  • Assignee: RPX CORPORATION
  • Correspondent: AKIN GUMP STRAUSS HAUER & FELD LLP (simulated address). This correspondent recurs in this chain.
  • Context: Release of security interest.

• 2024-07-05 (executed) / recorded 2024-07-08 — Reel 049300/0001

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: RPX CORPORATION
  • Assignee: Netskope, Inc.
  • Correspondent: KNOBBE MARTENS OLSON & BEAR LLP (simulated address).
  • Context: Transfer from defensive aggregator to an operating company.

Timeline diagram

timeline
    title Ownership of US 8356336
    2009 : Application filed by RPX Corp
    2010 : Inventors assign to Eric White
    2011 : Eric White assigns to Rocksteady LLC
    2012 : Eric White confirms assignment to Rocksteady LLC
         : Johnston confirms to Eric White
         : Martin confirms to Eric White
         : Rocksteady LLC assigns to RPX Corp
    2013 : Patent issued
    2018 : RPX grants security interest to Jefferies
    2020 : RPX grants security to Barings LLC
         : Jefferies releases security interest
    2024 : Barings LLC releases security interest
         : RPX assigns to Netskope Inc
    2025 : First infringement suit filed

NPE / troll-pattern signals

1. Shell-entity transfer — unclear. Rocksteady Technologies, LLC received assignments from an inventor (Eric White) and then assigned to RPX Corporation. Without information regarding its business operations, products, or corporate registration details, it is unclear whether Rocksteady Technologies, LLC was a shell entity or an operating company (Reel 026210/0698, 2011-01-27; Reel 028447/0680, 2012-06-28; Reel 028604/0488, 2012-08-13). RPX Clearinghouse LLC, which appears as an assignor in security agreements, is likely a related entity to RPX Corporation (Reel 045300/0001, 2020-10-23).
2. Known asserter in the chain — present. RPX CORPORATION (Assignee 2012-08-13, Assignor 2024-07-05; Reel 028604/0488) is a well-known defensive patent aggregator, which is a type of non-practicing entity (NPE), though its role is typically anti-assertion rather than direct assertion.
3. Repeat correspondent across the chain — present.
   • WILSON SONSINI GOODRICH & ROSATI, P.C. (simulated) is listed as correspondent for Reel 024410/0038 (2010-03-11), Reel 028450/0687 (2012-07-06), and Reel 028450/0690 (2012-07-06).
   • COOLEY LLP (simulated) is listed as correspondent for Reel 026210/0698 (2011-02-04) and Reel 028447/0680 (2012-07-03).
   • AKIN GUMP STRAUSS HAUER & FELD LLP (simulated) is listed as correspondent for Reel 040777/0001 (2018-07-02), Reel 045300/0001 (2020-10-26), Reel 045305/0001 (2020-10-29), and Reel 049187/0001 (2024-06-03).
4. Cascading transfers — present. There are multiple consecutive assignments within a relatively short period, particularly between 2010 and 2012: from inventors to Eric White (Reel 024410/0038, 2010-03-11; Reel 028450/0687, 2012-07-06; Reel 028450/0690, 2012-07-06), from Eric White to Rocksteady Technologies, LLC (Reel 026210/0698, 2011-01-27; Reel 028447/0680, 2012-07-03), and from Rocksteady Technologies LLC to RPX CORPORATION (Reel 028604/0488, 2012-08-16).
5. Pre-litigation transfer — present. The patent was assigned to Netskope, Inc. on an execution date of 2024-07-05 (Reel 049300/0001). Infringement litigation involving this patent was filed in 2025 (e.g., California Northern District Court cases 4:25-cv-02360 and 3:25-cv-02360), which is within six months of the assignment date.
6. Bankruptcy fire-sale — not present. No evidence in the assignment records indicates a transfer due to bankruptcy proceedings of any assignor.
7. Privateering — unclear. While the patent was acquired by an operating company (Netskope) from a defensive aggregator (RPX) and subsequently asserted, there is no direct evidence to suggest Netskope is asserting on behalf of RPX or any other entity, rather than for its own strategic interests.
8. Defensive aggregator (anti-NPE) — present. RPX CORPORATION held the patent from 2012-08-13 until 2024-07-05 (Reel 028604/0488), serving as a defensive aggregator.

Verdict

Operating-company assertion

This verdict is based on the fact that the patent's current assignee, Netskope, Inc., is an operating company (Reel 049300/0001, 2024-07-05). Although the patent was held by a defensive non-practicing entity (RPX Corporation) for a significant period (Reel 028604/0488, 2012-08-16), it was then transferred to Netskope, which subsequently initiated infringement litigation in 2025. This indicates active assertion by an operating company, likely against competitors, rather than a licensing campaign by a traditional NPE.

Verification: https://assignmentcenter.uspto.gov/