Regulators around the world from Europe to Asia ramped up efforts to bring about formal laws for digital currencies in 2023 — but it was the U.S. that took some of the harshest legal actions against major players in the industry.

According to CNBC, in a year that saw crypto heavyweight Binance ordered to pay more than $4bn to U.S. authorities and its former Chief Executive Officer’s guilty plea, along with high-profile lawsuits against five crypto companies by the Securities and Exchange Commission, regulators overseas have been equally busy both adopting new legislation — and pushing for more — to rein in the sector’s bad actors.

The U.S. has proven to be one of the most active enforcers of penalties and legal action against crypto companies this year, as authorities looked to counter bad practices in the industry following the collapse of Sam Bankman-Fried’s crypto empire — including his FTX exchange and sister firm Alameda Research.

“To be clear, in some cases — like FTX — enforcement was necessary,” said Renato Mariotti, a former prosecutor in the U.S. Justice Department’s Securities and Commodities Fraud Section. “But U.S. enforcement actions against market participants that are more focused on compliance are questionable and the result of the U.S. ‘regulation by enforcement’ approach.”

While many regions have passed laws with potentially tough penalties, the U.S. is still the only country that has actively taken action against large-scale crypto companies and projects. Thus far, the U.S. has led that campaign against crypto firms by enforcement and has, by far, been the most punishing of regulators when it comes to penalties and fines.

“Other countries have a comprehensive regulatory framework in place. We don’t,” Mariotti told CNBC. “As a result, issues that should be determined by legislation or regulation are instead litigated.”

Indeed, in the absence of hard-and-fast rules from Capitol Hill, the SEC, the Commodity Futures Trading Commission, the Department of Justice, and Treasury’s Financial Crimes Enforcement Network, have worked in parallel to police the space, in a sort of patch-quilt version of regulation-by-enforcement.

Richard Levin, a partner at Nelson Mullins Riley & Scarborough who has represented clients before the SEC, CFTC, and Congress, tells CNBC that these agencies have been some of the most active enforcers around the world concerning the regulation of digital assets and cryptocurrencies.

“These agencies have provided guidance to the industry on how digital assets and cryptocurrencies must be offered and sold, traded, and held by custodians,” said Levin, who has been involved in the fintech sector for 30 years.

“However, much of their work has involved providing guidance to the industry through enforcement actions,” continued Levin.

Since 2019, Justice’s Market Integrity and Major Frauds Unit has charged cryptocurrency fraud cases involving over $2bn in intended financial losses to investors worldwide.