Brooklyn prosecutors and the FBI have seized or disrupted 241 websites and 112 servers tied to a crypto investment scam that allegedly stole tens of millions of dollars from Russian-speaking victims in the U.S.

The operation, carried out last week, came after a three-year investigation into a fraud network that relied on online infrastructure and IP addresses in Ukraine and other Eastern European countries, Brooklyn District Attorney Eric Gonzalez said. No arrests were announced.

The scammers drew victims through Russian-language Facebook ads that promised investment opportunities. Fake advisers then called the victims and coached them to buy cryptocurrency and send it to fraudulent trading platforms.

When victims tried to withdraw their…