Notable lawsuit against @Tether_to just filed in the SDNY days ago. This was brought by a company that used Tether and woke up one morning to find $45mm in funds frozen, allegedly due to an informal request by Bulgarian law enforcement.

Riverstone alleges that Tether falsely markets USDT as a reliable and liquid stablecoin, while maintaining centralized control over user funds through smart contracts that allow Tether to freeze or blacklist wallet addresses. Despite advertising USDT as fast, stable, and free from banking delays, Tether allegedly exercised unilateral control inconsistent with these claims.

(Ed. note: These "false marketing" allegations seem dubious. It isn't exactly a secret that Tether has complete control over the use of Tether. But maybe some of their marketing is misleading (?). Anyways . . . )

Riverstone claims eight of its wallets were frozen on April 4, 2025, after Tether received a request from a Bulgarian police department. Tether did not provide the plaintiff with legal documentation justifying the freeze and instead directed Riverstone to contact Bulgarian authorities, who allegedly failed to respond.

Curiously, and possibly relatedly, I found this article (date unknown) from a Bulgarian law firm (https://posolstvo.eu, which focuses on immigration issues of all things) talking about how to get your Tether unfrozen after Tether responds to an informal request to freeze. "So why is Tether blocking USDT addresses? Most often, the ban is requested by law enforcement agencies from around the world. In the last months, for example, we are receiving huge amount of reports that the Chinese authorities have been requesting many of the USDT freezes. Traditionally, the FBI is also requesting USDT bans to be put on addresses with suspicious (according to them) activities. Many other state security agencies from around the world are also requesting Tether to freeze addresses. The problem is that many of these requests are not legally justified. Additionally, Tether is not able to justify the authority of each foreign security agency and their legality. This leads to the overwhelming amount of requests to be honoured by Tether." A pretty thorough and thoughtful article for an immigration law firm!

Now back to the complaint, which asserts that Tether:

i) Violated international legal protocols by freezing assets solely based on a local Bulgarian police request without proper judicial or diplomatic process;

ii) Failed to act in good faith or provide due process before restricting access to Riverstone’s funds; and

iii) Earned interest from the reserves backing USDT during the freeze, enriching itself unjustly.

Causes of Action include (i) Breach of Fiduciary Duty: (Tether allegedly owed a fiduciary duty as issuer and custodian of USDT, including safeguarding Riverstone’s assets, ensuring liquidity, and maintaining transferability); (ii) Unjust Enrichment (By profiting from reserve interest while denying Riverstone access to its assets); and (iii) Conversion (Tether allegedly exercised unauthorized control over Riverstone’s property by freezing its wallets and restricting transfer of funds).

How to freeze stablecoins is a really important issue if we are entering the era of stablecoin proliferation! Many in the crypto security community are highly critical of @circle for failing to stop laundered funds of which they may have full awareness because they have yet to receive legal process.

@Tether_to appears (by all reports I've heard) to be much more accommodating to law enforcement requests received on the fly - which the security/fund chaser folk love frankly - but this is all done with the risk that they are overinclusive and block someone's funds who aren't scammers/hackers. Kudos to Tether for being more aggressive with stopping illegal flows (and who can blame them given how much bad guys use Tether) but this just seems frankly unsustainable to do it informally.

Banks/financial services will block/seize only pursuant to a prescribed legal process, and only because the law affords them protections against customer complaints when they follow that process. That's why its slow but at least the banks aren't risking liability all the time. There is nothing similar in crypto. Maybe you simply can't stop laundering if there was something similar in crypto. Maybe some new approach is needed.

This is one to watch! I think Tether just hands over the funds and moots the case assuming Bulgaria backs down - or the Bulgarian authorities paper over this with process to make it above board. We shall see.