PACSEC3 v. Opswat: Voluntary Dismissal With Prejudice in Firewall Patent Dispute
PACSEC3, LLC brought a patent infringement action against cybersecurity firm Opswat, Inc. in the Middle District of Florida, asserting US7523497B2 covering packet flooding defense and firewall systems. Before Opswat answered or moved for summary judgment, PACSEC3 voluntarily dismissed all claims with prejudice — closing the door on re-litigation of this patent within 148 days of filing.
Pre-Answer Dismissal With Prejudice Ends PACSEC3’s Firewall Patent Claim
On 20 October 2024, PACSEC3, LLC filed suit against Opswat, Inc. in the United States District Court for the Middle District of Florida, asserting infringement of US7523497B2 — a patent covering packet flooding defense mechanisms and related firewall systems. Opswat, a Tampa-based cybersecurity company known for its endpoint security and network access control products, was alleged to infringe through its website and product instruction manuals. The case was assigned case number 8:24-cv-02425.
The case closed on 17 March 2025 after PACSEC3 filed a notice of voluntary dismissal pursuant to Federal Rule of Civil Procedure 41(a)(1)(A)(i), which permits a plaintiff to dismiss an action without a court order before the defendant has served an answer or a motion for summary judgment. Crucially, PACSEC3 expressly designated the dismissal as with prejudice as to the asserted patent, which goes beyond the default Rule 41 outcome — a deliberate choice that permanently bars PACSEC3 from re-asserting US7523497B2 against Opswat.
At 148 days, the resolution is notably swift and occurred at the earliest possible procedural stage. The public record does not disclose whether a settlement agreement or licensing arrangement accompanied the dismissal; the stipulation that each party bears its own costs is consistent with either a negotiated resolution or a unilateral decision to abandon the claim. The with-prejudice designation, self-imposed by the plaintiff, is the most commercially significant feature of this disposition — it suggests PACSEC3 may have concluded the claim lacked merit against Opswat’s specific products, or that a separate commercial arrangement made litigation unnecessary.
Filing to Voluntary dismissal in 148 days
148 days — resolved before defendant filed any responsive pleading
Dismissed with prejudice: what the voluntary exit means for both parties
Rule 41(a)(1)(A)(i): plaintiff’s unilateral right to exit
Federal Rule 41(a)(1)(A)(i) allows a plaintiff to dismiss an action without a court order — and without the defendant’s consent — before the defendant serves an answer or a motion for summary judgment. PACSEC3 invoked this right here. The distinguishing feature is that PACSEC3 voluntarily elected a with-prejudice designation, converting what would otherwise be a dismissal without prejudice into a permanent bar on re-filing the same claims against Opswat on this patent.
Pre-answer voluntary dismissalWith prejudice: PACSEC3 cannot re-assert this patent against Opswat
A dismissal with prejudice operates as a final adjudication on the merits, precluding the same plaintiff from bringing the same claims again. By expressly specifying with prejudice as to the asserted patent, PACSEC3 permanently surrendered its right to sue Opswat under US7523497B2. This is a meaningful concession. Whether it reflects a negotiated outcome, a licensing arrangement, or a strategic reassessment of claim viability against Opswat’s specific products and manuals is not disclosed in the public record.
Permanent bar on re-assertionOpswat exits without admitting infringement or paying awarded costs
Opswat, Inc. was never required to answer the complaint or file any dispositive motion before the case ended. The cost-neutral outcome — each party bearing its own fees — means Opswat incurred litigation costs without any court-ordered recovery. However, Opswat gains permanent protection from PACSEC3 re-asserting US7523497B2 against it. The patent’s validity was not adjudicated, leaving Opswat’s freedom to operate dependent on the patent’s continued enforceability against other parties.
No admission; patent not invalidatedUS7523497B2 remains live — third-party infringement risk persists
The dismissal with prejudice only binds PACSEC3 and Opswat. US7523497B2 survives as an enforceable patent, and PACSEC3 retains the right to assert it against any other firewall or packet-flooding-defense product vendor. Competitors operating in the network security and firewall segment — particularly those with products addressing packet flooding or DDoS mitigation — should treat this patent as an active enforcement risk and consider running FTO analysis against its claims.
Patent remains enforceable vs. third partiesFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | PACSEC3, LLC | Company | Cybersecurity patent holder — holder of US7523497B2 covering packet flooding defenseSearch in Eureka ↗ |
| Defendant | Opswat, Inc. | Company | Opswat, Inc. — Tampa-based cybersecurity firm specialising in endpoint and network securitySearch in Eureka ↗ |
| Plaintiff counsel | Victoria Elisabeth Brieant | Attorney | Counsel for PACSEC3, LLCSearch in Eureka ↗ |
| Plaintiff law firm | Law Office of Victoria E. Brieant PA | Law Firm | Representing PACSEC3, LLCSearch in Eureka ↗ |
| Defendant counsel | Ardith Bronson | Attorney | Counsel for Opswat, Inc.Search in Eureka ↗ |
| Defendant counsel | Michael Strapp | Attorney | Counsel for Opswat, Inc.Search in Eureka ↗ |
| Defendant law firm | DLA Piper US LLP | Law Firm | Representing Opswat, Inc.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Florida Middle District CourtSearch in Eureka ↗ |
Official order — verbatim text
PACSEC3’s notice expressly invokes Rule 41(a)(1)(A)(i) and designates the dismissal as with prejudice as to the asserted patent — language that goes beyond the rule’s default. Under Rule 41(a)(1)(B), a voluntary dismissal is presumptively without prejudice unless the plaintiff specifies otherwise or has previously dismissed the same claim. PACSEC3’s affirmative choice to add the with-prejudice qualifier here is the critical operative language: it converts this procedural exit into a permanent merits bar, fully protecting Opswat from any future claim by PACSEC3 on US7523497B2.
US7523497B2 — Packet Flooding Defense and Firewall Systems
US7523497B2, filed under application number US10/841064, covers technology directed at defending networks against packet flooding attacks — a foundational threat vector encompassing SYN floods, UDP floods, and related denial-of-service techniques. The patent’s claims relate to systems and methods for detecting and mitigating high-volume unsolicited packet traffic at the network perimeter, a domain central to firewall architecture and intrusion prevention systems. The application pre-dates the modern DDoS mitigation market and represents an early-generation patent in what is now a high-value commercial space.
Strategically, US7523497B2 sits at the intersection of network perimeter security and traffic management — two areas that have seen significant commercial investment and product development since the patent’s priority date. For vendors of next-generation firewalls, unified threat management platforms, or dedicated anti-DDoS appliances, the claims of this patent warrant careful review. The fact that PACSEC3 targeted Opswat’s product instruction manuals as evidence of infringement suggests the asserted claims may map onto product-level functionality descriptions, which broadens the potential exposure universe considerably.
Should your network security product be cleared against US7523497B2?
Any company developing, selling, or distributing firewall systems, packet flood mitigation tools, or network intrusion prevention products should assess exposure to US7523497B2. PACSEC3’s assertion specifically targeted a cybersecurity vendor’s products via its documentation and website — a low-threshold evidentiary approach that suggests broad claim interpretation. Products that defend against SYN floods, UDP floods, or volumetric DDoS attacks at the network layer are most likely within scope of the claims as asserted.
PatSnap Eureka’s FTO Search Agent can map the claims of US7523497B2 against your specific product architecture, identify prior art that may limit claim scope, and surface any continuation or related applications that PACSEC3 may hold in the same family. Given that this patent remains enforceable following the Opswat dismissal, running a structured FTO before product launch or market expansion in the network security segment is a proportionate and commercially prudent step.
Run a freedom-to-operate analysis on US7523497B2 to assess your product’s exposure
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What this case signals for the cybersecurity patent enforcement landscape
A pre-answer with-prejudice exit is an unusual move — it raises questions about PACSEC3’s enforcement strategy and Opswat’s exposure going forward.
Pre-answer dismissals with prejudice suggest negotiated resolutions or claim reassessment
When a plaintiff voluntarily dismisses with prejudice before the defendant has even responded, it typically signals either a licensing deal was reached off-record, or the plaintiff concluded its infringement theory was unlikely to succeed against that specific defendant’s products. Either reading is commercially significant for competitors monitoring PACSEC3’s enforcement behaviour around US7523497B2.
US7523497B2 remains a live enforcement asset — FTO is not resolved by this case
This dismissal did not invalidate US7523497B2 or narrow its claims. Network security vendors offering firewall, packet-flood mitigation, or DDoS defence products cannot rely on this outcome for freedom-to-operate comfort. A targeted FTO analysis against the claims of US7523497B2 is warranted for any company operating in this product segment.
PACSEC3 v Opswat — key questions answered
PACSEC3, LLC filed a patent infringement action against Opswat, Inc. in the Middle District of Florida asserting US7523497B2, which covers packet flooding defense and firewall systems. PACSEC3 alleged infringement through Opswat’s website and product instruction manuals. The case was voluntarily dismissed with prejudice by PACSEC3 after 148 days, before Opswat filed any responsive pleading.
The with-prejudice designation means PACSEC3 is permanently barred from re-asserting US7523497B2 against Opswat in any future litigation. It operates as a final adjudication on the merits for purposes of claim preclusion. Opswat did not admit infringement, and the patent’s validity was not adjudicated. Each party bears its own legal costs under the dismissal terms.
No. A voluntary dismissal with prejudice does not constitute a finding of invalidity or unenforceability. US7523497B2 remains an active, enforceable patent. PACSEC3 retains full rights to assert it against other parties. Network security vendors with products in the firewall or packet flooding defense space should not treat this dismissal as clearing the patent’s enforceability against them.
Federal Rule of Civil Procedure 41(a)(1)(A)(i) permits a plaintiff to dismiss an action without a court order, and without the defendant’s consent, before the defendant has served an answer or a motion for summary judgment. PACSEC3 invoked this rule here. Ordinarily such a dismissal would be without prejudice, but PACSEC3 expressly designated it with prejudice — a voluntary and binding concession that permanently forecloses re-litigation of these specific claims against Opswat.
According to the case record, PACSEC3 alleged infringement through Opswat’s website and product instruction manuals relating to packet flooding defense and firewall systems. Opswat is known for endpoint security, network access control, and related cybersecurity products. The specific product lines or features alleged to practise the claims of US7523497B2 were not publicly detailed beyond these references in the case record.
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