ZkSNACKs is shutting down its Coinjoin service, which helps anonymize crypto transactions, beginning June 1.

The wallet developer is withdrawing support for transaction privacy service Coinjoin amid mounting pressures from law enforcement, as U.S. regulators and authorities crack down on coin mixers and other tools that obfuscate crypto transactions. The shutdown comes shortly after authorities arrested the co-founders of Samurai Wallet, which is also limked to coinjoin.

So-called coin mixers obfuscate the origins and destinations of crypto transactions, making it difficult for international authorities to identify dark money laundering. While Coinjoin bills its tools as more complex, and entirely different from,  coin mixers, its tech is used to the same effect as traditional mixing services. 

ZkSNACKs' shuttering of its privacy-focused transaction tool follows other moves the project has taken to limit its legal liabilities stateside. Last week, ZkSNACKs blocked access to its Wasabi Wallet for U.S. citizens and residents.

Crypto firms’ sunsetting of legally ambiguous products in the U.S. underscores growing concerns over authorities’ hostility toward some cryptocurrency services in the U.S. Last year, U.S. law enforcement arrested Tornado Cash developer Roman Storm on money laundering and wire fraud conspiracy charges related to his platform’s token mixing services.

UPDATE: Adds nuance to the article, acknowledging Coinjoin's assertions that its offering differs from that of a tradional coin-mixing service. (16:54 ET)