Tether Froze $42.4M in USDT on an Informal HSI Request, Warrant Came Later

A federal lawsuit exposes what happens when a stablecoin issuer doubles as an informal enforcement arm: your funds disappear first, the paperwork comes later.

Key takeaways

• Tether blacklisted 10 Ethereum wallets holding exactly $42,417,785.62 in USDT on October 30, 2025, allegedly at the informal request of a Homeland Security Investigations agent. No warrant, court order, or subpoena existed at the time.
• A seizure warrant (5:26-MJ-1267-JG) was issued by a magistrate judge in the Eastern District of North Carolina on February 19, 2026, more than three months after the freeze. The plaintiffs argue it cannot retroactively authorize what was already done.
• The complaint also alleges Tether continued earning Treasury yield on the reserves backing the frozen tokens throughout the entire hold period, a financial incentive embedded in the company's business model to cooperate and hold.

Two Thai nationals, Nutthawat Rukthammachalern and Natthawat Kasamvilas, filed suit against Tether in the U.S. District Court for the Southern District of New York on August 31, 2026, first reported by CoinDesk. The complaint alleges that Tether's addBlackList function, a unilateral smart-contract capability built into its Ethereum-based token, was triggered without any legal process authorizing it, leaving the plaintiffs locked out of $42.4 million for more than three months before a court ever reviewed the underlying evidence.

The underlying investigation centers on a pig-butchering fraud scheme traced by HSI out of North Carolina. The complaint does not contest those criminal allegations. What it contests is Tether's conduct as a private company, specifically whether a phone call from a federal agent is sufficient legal basis to freeze tokens held by third parties who have no contractual relationship with Tether at all.

The 112-Day Gap

October 30, 2025: Tether triggers addBlackList on 10 Ethereum addresses. February 19, 2026: magistrate judge issues warrant 5:26-MJ-1267-JG in the Eastern District of North Carolina. That is 112 days. More than three months during which $42.4 million was functionally nonexistent for its holders, with no court having reviewed the evidence.

Five days after the warrant, the DOJ and HSI announced the seizure of more than $61 million in USDT connected to the broader investigation. The warrant itself directed Tether to burn the USDT at the flagged addresses using its destroyBlackFunds function, mint an equivalent amount of new USDT, and transfer those tokens to a government-controlled wallet. Tether acted as an agent of destruction and re-creation on behalf of the government, before a final forfeiture judgment.

As of the complaint's filing date, the plaintiffs' $42.4 million remains frozen, not confirmed transferred to any government wallet.

What This Case Actually Reveals

The plaintiffs were secondary-market USDT holders. They had no account with Tether, no terms of service with Tether, no contractual relationship of any kind. That fact makes the property-rights question sharper than any prior Tether enforcement action.

Tether's position, implicit in its cooperation, is that it retains legal authority over every USDT token at all times regardless of who holds it. The complaint, filed under claims of conversion, trespass to chattels, unjust enrichment, and declaratory and injunctive relief, argues the opposite.

The unjust enrichment claim deserves more attention than it has received. Tether holds U.S. Treasuries as reserves backing every USDT in circulation. While the plaintiffs' tokens were frozen, the plaintiffs allege Tether continued earning yield on those reserves.

The complaint alleges the company profited from the freeze itself. That is not a technicality; it describes a financial incentive structure that rewards cooperation with informal law-enforcement requests and penalizes nothing about holding someone else's funds indefinitely.

The complaint also invokes New York's revised Uniform Commercial Code Article 12, which treats USDT as a "controllable electronic record" and argues the plaintiffs acquired it as good-faith purchasers entitled to protection. If a court accepts that framing, Tether's addBlackList capability becomes not just a technical feature but a potential unauthorized interference with protected property. The implications extend well beyond this case.

This is the failure mode SEC crypto custody reform debates have circled around in the abstract: a centralized issuer with a unilateral freeze function becomes, in practice, an extension of the surveillance state. A freeze can precede any warrant, with the paperwork following after. The Tether-OFAC sanctions pattern already showed Tether operating as a compliance arm for the U.S. government. This lawsuit is the first time someone is contesting that arrangement in federal court on behalf of holders who never signed up for it.

Bitcoin's base protocol has no addBlackList function. No issuer exists to receive an informal phone call. That is not an ideological point; it is a technical fact that this lawsuit makes concrete.

What to Watch

The SDNY case will turn first on whether the court accepts jurisdiction and how Tether responds. The parallel motion filed July 31, 2026 in North Carolina seeking immediate return of the USDT adds procedural pressure. The legal wildcard is the UCC Article 12 argument: if the court recognizes secondary-market USDT holders as good-faith purchasers of a controllable electronic record, every future Tether blacklisting faces a higher legal bar. Watch for Tether's initial response filing, which will almost certainly argue it froze its own property rather than the plaintiffs', and that the due-process issue belongs to the government's seizure mechanics, not to Tether's cooperation.

Sources

• U.S. District Court, SDNY, complaint filed August 31, 2026 (searchable via PACER under plaintiffs' names)
• Seizure Warrant 5:26-MJ-1267-JG, Eastern District of North Carolina, February 19, 2026
• First reported by CoinDesk