In a 4,600-word open letter to the Financial Crimes Enforcement Network of the U.S. Treasury Department that has gone viral, Twitter founder and Square, Inc. CEO Jack Dorsey ripped the proposed regulations of Bitcoin and other crypto-currencies.

Dorsey said the proposed regulations would require companies handling crypto-currency transactions to compile the names and address of those making transactions valued at more than $3,000 as part of an effort to track possible funding of illegal activity.

“Were the proposal to be implemented as written,” Dorsey wrote, “Square would be required to collect unreliable data about people who have not opted into our service, or signed up as our customers.”

Jack Dorsey Bitcoin endorsement Twitter
Twitter chief executive officer Jack Dorsey has said he is “passionate” about Bitcoin after the online cryptocurrency experienced a volatile week. Drew Angerer/Getty

He said the proposed rule would unfairly target users of crypto-currencies and treat Bitcoin and cash differently.

Dorsey offered an example of what he sees as a contradiction in the proposed regulation.

“If a Square customer’s mother gifts her daughter $4,000 in physical cash and the daughter deposits those funds in a bank,” Dorsey said, “the bank would have no obligation to collect information on the customer’s mother.”

But, Dorsey pointed out, it would be a different story if the mother-to-daughter gift was not made in cash.

“Under the proposal,” Dorsey said, “if this same transaction were completed in crypto-currenc