Assignment history

Inventors

• Graham Merrett: The sole inventor listed on the patent. At the time of the original priority filing in 2007, an employer is not specified in the patent documents. However, given that Rembrandt Messaging Technologies LP was the original assignee, Merrett was likely an employee of or consultant for Rembrandt or an affiliated entity. There are no unusual patterns discernible from the patent record.

Original assignee

• Rembrandt Messaging Technologies LP: This is the entity named on the face of the issued US patent 11,991,600. Rembrandt Messaging Technologies is a well-documented non-practicing entity (NPE) or "patent troll," formed to acquire and assert a portfolio of messaging patents. The entity has never shipped a commercial product embodying the claims. It has been involved in numerous patent assertion campaigns over the last two decades. The entity's primary business is patent licensing and litigation. Its current status is that of a holding company that has transferred its operating assets to other assertion entities.

Assignment timeline

A search of the USPTO Patent Assignment Search database for the application family of US 11,991,600 (dating back to application Ser. No. 12/452,883) reveals the following ownership transfers.

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• 2020-05-18 (executed) / recorded 2020-05-19 — Reel 045155/0749

  • Conveyance: ASSIGNMENT OF ASSIGNOR'S INTEREST
  • Assignor: REMBRANDT MESSAGING TECHNOLOGIES, L.P.
  • Assignee: HBCU MESSAGING IP LLC
  • Correspondent: Ryan E. Daws, Servilla Whitney LLC, 33 WOOD AVE SOUTH, SUITE 830, ISELIN, NJ, 08830
  • Context: This was the initial transfer of the patent family from the original asserter to a new special-purpose entity. Note: This assignment was superseded by a corrective assignment recorded later.

• 2020-05-18 (executed) / recorded 2020-11-19 — Reel 055171/0173

  • Conveyance: NUNC PRO TUNC ASSIGNMENT
  • Assignor: REMBRANDT MESSAGING TECHNOLOGIES, L.P.
  • Assignee: HBCU MESSAGING US LP
  • Correspondent: Matthew P. Barthal, BARTHAL & ASSOCIATES, PLLC, 100 M STREET, S.E. SUITE 600, WASHINGTON, DC, 20003
  • Context: This corrective ("nunc pro tunc") assignment formally establishes the current plaintiff, HBCU Messaging US LP, as the owner, replacing the LLC from the May 2020 recording.

• 2020-05-18 (executed) / recorded 2020-11-19 — Reel 055171/0187

  • Conveyance: SECURITY AGREEMENT
  • Assignor: HBCU MESSAGING US LP
  • Assignee: RPL HOLDINGS, LLC
  • Correspondent: Matthew P. Barthal, BARTHAL & ASSOCIATES, PLLC, 100 M STREET, S.E. SUITE 600, WASHINGTON, DC, 20003. (This is the same correspondent who recorded the preceding assignment.)
  • Context: This is a securitization of the patent asset; the owner (HBCU) granted a security interest to another party (RPL Holdings), likely as collateral for litigation funding.

Timeline diagram

timeline
    title Ownership of US 11991600
    2007 : Original priority application filed
    2008 : PCT application filed by Rembrandt
    2020 : Assigned to HBCU Messaging US LP
         : Security agreement with RPL Holdings
    2023 : Application for this patent filed
    2024 : Patent issues
         : First infringement suit filed

NPE / troll-pattern signals

1. Shell-entity transfer: Present. The patent family was moved from Rembrandt Messaging Technologies, L.P. to HBCU Messaging US LP, an entity with a name characteristic of a special-purpose assertion vehicle (Reel 055171/0173). The current assignee does not appear to have any products in commerce.

2. Known asserter in the chain: Present. The original assignee, Rembrandt Messaging Technologies, L.P., is a widely recognized NPE. The current assignee and plaintiff, HBCU Messaging US LP, is also identified as a patent asserter by industry trackers like Unified Patents.

3. Repeat correspondent across the chain: Present. Matthew P. Barthal of BARTHAL & ASSOCIATES, PLLC acted as the correspondent for both the corrective assignment to HBCU Messaging US LP (Reel 055171/0173) and the related Security Agreement with RPL Holdings, LLC (Reel 055171/0187). This indicates a coordinated legal strategy between the patent holder and its likely litigation funder.

4. Cascading transfers: Not present. While there was a corrective assignment, the record shows one primary ownership transfer, not a rapid series of transfers between shell LLCs.

5. Pre-litigation transfer: Not present. The transfer to the current asserter, HBCU Messaging US LP, was executed in May 2020. The litigation involving US 11,991,600 began in 2024, well outside the 6-month window. The transfer was clearly made in preparation for a future assertion campaign, but not immediately preceding this specific lawsuit.

6. Bankruptcy fire-sale: Not present. There is no indication of bankruptcy proceedings in the assignment record.

7. Privateering: Not present. The original assignee was not an operating company.

8. Defensive aggregator (anti-NPE): Not present. The chain does not involve any known defensive aggregators.

Verdict

NPE — high confidence

The ownership chain shows multiple, strong signals of non-practicing entity activity. The patent originated with a known NPE (Rembrandt) and was transferred to a special-purpose assertion entity (HBCU Messaging US LP) per assignment Reel 055171/0173. This entity is now asserting the patent. The presence of a contemporaneously executed security agreement (Reel 055171/0187) recorded by the same attorney further points to a professionally managed and funded litigation campaign, which is the defining business model of an NPE.

Verification Link: USPTO Patent Assignment Search for App. No. 12/452,883