Normally, such rules undergo a lengthy public process that involves months of feedback and revisions. But when FinCEN published the rule on Dec. 18, it said it wanted to move swiftly and allowed only 15 days for comments -- during a time period that included both Christmas and New Year’s Eve. As a rationale, FinCEN officials said the lack of oversight on some transactions was a national security threat.

The truncated comment period took Bitcoin advocates by surprise, said Kristin Smith, who leads the Blockchain Association, a cryptocurrency trade group. Smith said she had expected the Treasury to take several months, but it suddenly became an “all-hands-on-deck situation.” The organization in December threatened to sue Treasury for rushing the process.

Crypto advocates flooded FinCEN with comments, arguing that the process was rushed and the rules were unworkable. FinCEN to date has received about 7,600 public comments.

The U.S. Chamber of Commerce wrote that the rule would have “unintended long-term consequences” on the virtual currency industry. Hedge-fund manager Mike Novogratz’s Galaxy Digital Holdings LP also submitted comments excoriating the proposal.

Gemini, a crypto exchange founded by Cameron and Tyler Winklevoss -- the twins who settled a long-running dispute with Facebook Inc. founder Mark Zuckerberg over who had the idea for the social media network -- wrote that FinCEN’s proposal could actually increase money laundering by encouraging criminals to move all of their crypto activities to unregulated markets outside the U.S.

Republican lawmakers, including former Representative Cynthia Lummis, who is now a Wyoming senator; Arkansas Senator Tom Cotton and Democratic Representative Tulsi Gabbard of Hawaii, also reached out to Mnuchin in letters and phone calls to criticize the rule and short comment period.

Fight for the Future, a digital rights advocacy group, set up a website, called “Stop Financial Surveillance,” that said FinCEN’s proposal would “facilitate extremely intense financial surveillance on an unprecedented scale.” The site included a web form for users to easily send a comment to the Treasury, which product director Dayton Young said has been used more than 3,000 times.

Some individual virtual currency owners who didn’t give their names told FinCEN the rule would unfairly expand surveillance of American citizens.

The Treasury Department in January yielded to the pressure and ultimately extended the comment period to the end of March, leaving the matter to the Biden administration, which could make a decision later this year.

That for us was our moment of victory,” said Smith. “Crypto won.”