South Korea targets 26 Polymarket users in US$12.7 million suspected illegal gambling case

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2026/08/18: South Korea blocks Polymarket for alleged illegal gambling operations 2025/11/25: South Korean gambling crackdown clocks over 5,000 arrests 2026/07/15: Korean authorities aim to charge alleged head of massive illegal overseas gambling ring 2025/12/01: South Korea now arresting gang members for illegal igaming and cybercrime more often than other crimes

The Backstory

Polymarket case tests the boundary between betting and trading

South Korea’s move against 26 Polymarket users marks a sharper phase in a broader enforcement campaign that has increasingly treated online wagering, offshore platforms and crypto-enabled markets as connected risks. The case centers on about KRW17.6 billion, or $12.7 million, in suspected wagers and asks a question regulators globally have struggled to answer: when does an event contract become gambling rather than a financial or informational market?

The police theory is straightforward. If users stake digital assets on uncertain outcomes and either receive a payout or lose their stake depending on the result, authorities say the conduct can fall under Article 246 of South Korea’s Criminal Act. The users’ defense points in the other direction, emphasizing that Polymarket contracts can be traded before settlement and resemble derivatives-style instruments rather than fixed bets. No reported court ruling in the cases has resolved that distinction.

The stakes are larger than the 26 users now booked. A finding that prediction-market trades amount to illegal gambling would give investigators and regulators a template for pursuing similar platforms, especially where Korean users access services through crypto wallets, public blockchains and foreign websites rather than domestic payment rails or customer databases.

Access block came before the criminal referrals

The criminal case follows an administrative clampdown that had already pushed Polymarket outside normal domestic access channels. South Korea’s media regulator blocked the platform on Aug. 18 after concluding that its markets created an illegal gambling environment for domestic users. The Korea Media and Communications Standards Commission acted after months of review, including scrutiny of markets tied to politics, entertainment, sports, economics and weather.

That decision was previewed in South Korea’s earlier block of Polymarket for alleged illegal gambling operations, which showed regulators focusing on the platform’s basic structure: users buy “Yes” or “No” positions tied to real-world outcomes. The commission characterized the model as a winner-take-all profit-and-loss structure based on chance. Polymarket disputed the conclusion, arguing it had removed Korean-language services and disabled won payments, and therefore should not be treated as operating under South Korean law.

The regulator rejected that view, saying technical design and service methods do not excuse compliance where Korean users can still access an illegal gambling environment. That reasoning matters for the police inquiry now under way. It suggests authorities are not limiting jurisdictional analysis to whether a platform has a local office, Korean bank relationships or direct marketing in the country. Instead, they are looking at functional access, user conduct and the economic substance of the transaction.

Investigators are following digital trails

The Polymarket matter also shows how South Korean enforcement has adapted to platforms without conventional domestic account records. Police said investigators relied on public blockchain transactions and open-source intelligence to identify users because Polymarket operates through a non-custodial, peer-to-peer structure and does not maintain a typical local customer database. That approach reflects a wider shift in gambling investigations: enforcement is moving from storefront raids and bank subpoenas toward data tracing, wallet analysis and cross-platform intelligence.

South Korea’s gambling laws have long restricted unauthorized wagering, but the practical challenge has changed. Offshore operators can serve Korean users without local servers or visible corporate assets. Crypto-based platforms add another layer by reducing reliance on traditional payments. Authorities’ ability to turn public blockchain activity into identifiable cases will be closely watched by users of prediction markets, offshore casinos and digital-asset wagering sites.

The method also raises evidentiary and policy questions. Blockchain transactions may show transfers and trades, but investigators still must connect wallets to individuals and establish the legal character of the activity. In Polymarket’s case, that means proving not only who traded but whether the event contracts meet the statutory definition of gambling. The absence of a settled ruling leaves prosecutors with a potentially influential test case.

Crackdown has widened beyond platform operators

The Polymarket investigation lands during one of South Korea’s more aggressive periods of online gambling enforcement. Police have been pursuing both operators and users, with officials framing illegal gambling as a cybercrime problem tied to organized networks, youth exposure and overseas infrastructure.

In one recent sweep, authorities reported more than 5,000 arrests in a year-long gambling crackdown, recovering KRW123.5 billion in illegal gambling revenue. More than half of those arrested were in their 20s or 30s, while thousands of minors were identified as participants. The enforcement campaign is expected to continue through October 2026, with an emphasis on illegal sites based overseas.

That context helps explain why the Polymarket case is not being treated as a niche dispute over financial innovation. For Korean authorities, online betting has become a mass-market enforcement concern, with young adults and minors increasingly exposed through phones, social media and foreign platforms. Even if prediction-market users see themselves as traders, regulators are likely to measure the product against the same public-policy concerns driving the wider crackdown: addiction risk, unlicensed wagering, consumer losses and difficulty recovering proceeds.

Recent cases have also shown authorities targeting the infrastructure behind online gambling. Police arrested a group linked to 153 illegal gambling sites and virtual betting-money distribution, saying developers, distributors and operators divided functions across a supply chain. In another case, officials moved to charge the alleged head of a massive overseas gambling ring linked to billions in wagers that operated from Malaysia and Cambodia. Those investigations underscore a common enforcement theme: Korean authorities are trying to cut off not just individual sites but the systems that let them scale.

Organized crime concerns add pressure

The political pressure behind these cases has intensified as police connect illegal igaming with broader cybercrime and organized crime trends. The Korean National Police Agency reported that, for the first time, gang members were arrested more often for online scams, including illegal igaming, than for traditional crimes such as assault or extortion. The shift was detailed in reporting on gang-linked arrests increasingly tied to illegal igaming and cybercrime.

That development changes the enforcement calculus. Illegal gambling is no longer framed only as vice activity or consumer misconduct. It is increasingly described as a revenue stream for organized groups that can operate across borders, recruit younger members and scale quickly through digital tools. Police say these networks often retain hierarchical structures, with senior figures collecting profits generated by lower-tier participants, while the underlying activity shifts from street-level intimidation to online fraud and gambling.

For prediction markets, that association creates regulatory headwinds even when platforms present themselves as transparent, decentralized or information-driven. Authorities are likely to focus less on the platform’s self-description and more on whether the product enables Korean users to risk value on uncertain outcomes without licensing, oversight or consumer safeguards. If the activity resembles the economic outcome of a bet, regulators may be inclined to fold it into the same enforcement framework applied to offshore casino sites.

Global dispute reaches Korean courts and regulators

The South Korean action is part of a wider international dispute over how to classify prediction markets. Polymarket and similar platforms argue that event contracts aggregate information and can be traded before expiration, making them distinct from traditional betting. Gambling regulators counter that many contracts mimic wagers because users profit or lose based on real-world outcomes, including elections, sports and other contingent events.

South Korea’s position has so far leaned toward the gambling interpretation. The access block, the user investigations and the reliance on criminal-law provisions all point in that direction. But the unresolved legal issue remains significant. A court decision accepting the derivatives-style argument would complicate enforcement and could force lawmakers or regulators to define prediction markets more precisely. A ruling favoring prosecutors could chill domestic use of foreign event-contract platforms and support further blocking orders.

The case also illustrates the limits of geo-compliance as a defense. Removing Korean-language support or local-currency payments may reduce evidence of targeting, but South Korean regulators have signaled that availability to domestic users can be enough when the service is deemed harmful or illegal. That approach could affect other offshore platforms whose products are accessible through decentralized tools, foreign domains or crypto wallets.

For users, the immediate risk is personal exposure. South Korean enforcement has historically focused heavily on operators, but the Polymarket case shows that high-volume users can also draw scrutiny when authorities can trace activity. For platforms, the risk is that prediction markets may be pulled into gambling enforcement regimes before financial regulators create a separate category for them. Until courts or lawmakers settle the classification question, South Korea’s crackdown is likely to remain a warning to both sides of the market.