Korean authorities have arrested 80 people for allegedly modifying their Teslas to activate Full Self-Driving, a feature with tight restrictions in the country.

According to SlashGear, the suspects used DIY devices or units purchased and imported from places like Europe and China, plugged into or hardwired into the vehicle's systems.

They are charged under Korea's Motor Vehicle Management Act, which bans unauthorized software changes that could affect vehicle safety, and also allegedly shared online advice about unlocking the feature and hiding that it was activated.

If convicted, they face up to two years in prison and a fine of 20 million Korean won, around $15,000 USD, though they remain presumed innocent while Seoul police work with several agencies to investigate.

The rule turns on where the vehicle was built. Only Teslas made in the United States — the Model S, Model X, and Cybertruck — can legally have FSD active in Korea, because a free trade agreement recognizes US federal safety regulations and exempts them from Korean safety certification.

China-made models, including most Model 3 and Model Y vehicles sold there, lack the appropriate certifications.

SlashGear reports that under current Korean standards FSD-equipped cars can change lanes on their own, but drivers must keep their hands on the wheel and manually engage turn signals, whereas the feature opens up hands-free use — and regulators still note FSD is not actually autonomous and requires active supervision.

In a parallel development, Reuters reports that an advocacy group, Citizens United for Consumer Sovereignty, plans to file a complaint with the Korea Fair Trade Commission alleging Tesla misled tens of thousands of South Korean customers by marketing FSD (Supervised) it knew could not be legally used in most vehicles sold there.

Tesla Korea country manager Seo Young-deuk testified in parliament that FSD works on only about 20% of Teslas registered in the country, and data Tesla submitted to the National Assembly shows 99% of new Teslas sold there last year could not legally use FSD.

The group's Choi Young-suk said Tesla 'generated substantial revenue by selling an expensive driver-assistance system to mass-market buyers who cannot use it for even a single day.'

The complaint asks the KFTC to issue a temporary cease-and-desist order on marketing FSD for ineligible vehicles, impose administrative fines, and refer the case to state investigators.

Reuters reports the agency already launched a probe earlier this year into Tesla's FSD advertising and has received written responses from the company.

The money involved is significant: Tesla sold more than 170,000 Shanghai-produced vehicles in South Korea since 2023, collecting lump-sum payments of 9.043 million won ($6,726) before shifting to a 150,000-won monthly subscription in August, and it surpassed BMW this year as Korea's top imported-car brand.

A Seoul court last month dismissed an owners' refund lawsuit, saying regulatory restrictions limited Tesla's rollout, and Tesla only applied for FSD certification for China-made cars in late October after years of selling the software.