The agency’s warning stated that users should avoid crypto money transmitting services that are not registered as Money Services Businesses (MSBs) under US federal law.

Individuals should also avoid services that fail to comply with anti-money laundering (AML) requirements and do not collect know-your-customer (KYC) information.

Users should check whether a service is registered as an MSB with the US Treasury’s Financial Crimes Enforcement Network (FinCEN). However, even registration is not a government “recommendation, certification of legitimacy, or endorsement,” per the notice.

Third-party listings likewise do not represent government approval, as an app is not necessarily a legal service simply because it is listed on an app store.

Users are at risk because they could experience “financial disruptions” or loss of funds when authorities carry out enforcement efforts. The notice does not suggest that authorities will fine or penalize users or target users directly as part of enforcement actions.

Recent US actions

The FBI said it executed recent enforcement operations against unregistered crypto services, which are known due to the agency’s past announcements.

Many cases include charges related to the operation of an unlicensed money service business and money laundering.

Various agencies, including the FBI, took action against the Samourai Wallet on April 24 — seizing the website and arresting its two co-founders. Authorities charged the founders with operating an unlicensed money-transmitting business due to the Samourai Wallet offering coin-mixing features, which were allegedly used for money laundering.

Other past cases targeted the operators of coin mixers such as Tornado Cash, ChipMixer, and Helix, and the operators of foreign crypto exchanges such as Bitzlato and BTC-e.