Sasaeng: The Underground Economy of K-Pop Stalking

For years, specialized taxis have been reported waiting near entertainment agencies, concert venues, and other locations frequented by idols, waiting not for ordinary passengers, but for customers paying them to follow a celebrity's vehicle. Sasaeng is a K-pop term for obsessive fans who intrude into celebrities' private lives, often through stalking or unauthorized access to personal information. Some sasaeng activity has developed into organized networks in which location data, phone numbers, flight details, and transport services are exchanged or sold. In a small minority of cases, intense fandom crosses into stalking and privacy violations.

Sasaeng Is Not a Synonym for Hardcore Fan

K-pop frequently encourages forms of fan engagement that can produce strong parasocial relationships, but ordinary fandom and sasaeng behavior are fundamentally distinct. While dedicated fans engage in bulk album buying or fund advertising campaigns legally, sasaeng behavior crosses personal boundaries and can include stalking, privacy violations, or other illegal conduct. In 2012, a Korea JoongAng Daily investigation highlighted that sasaeng fans often compete to obtain the most up-to-date location information. Data itself has both monetary value and status value inside these networks. Knowing a private schedule or having an unlisted phone number provides prestige and exclusivity among peers, driving a market where information is treated as a social commodity.

When Stalking Becomes a Business

The most visible manifestation of this economy is the sasaeng taxi. These drivers provide dedicated transport for stalking, and the costs are substantial. In 2012, one sasaeng taxi driver quoted rates of 150,000 won for three hours, while a teenage fan admitted to spending about 1 million won a month following idols. The practice has persisted; as recently as 2024, Kim Jae-joong publicly criticized sasaeng taxis he said were waiting around his concert venue. The physical pursuit often involves reckless driving, with drivers themselves having described speeding and the constant risk of accidents as simply part of the job.

The Black Market of Private Data

But physical tailing is only the surface of the surveillance network. The deeper intrusion happens digitally. Historical reporting documented trading in private mobile phone numbers and even resident-registration information, and the surveillance economy continues to extend into commercial aviation.

A major police investigation reported in July 2025 by The Korea Herald uncovered an illegal brokerage network accessing and selling the flight itineraries of high-profile groups like BTS. An airline employee allegedly accessed celebrities' internal flight-booking information and passed it to accomplices, who resold it through social-media DMs and open chat rooms. Police alleged the employee received tens of millions of won from the illicit trade. Such booking data has reportedly been used to identify flights, book nearby seats, alter meal choices, change seat assignments or interfere with reservations, enabling unwanted proximity for hours in an environment where artists cannot simply leave.

Sasaeng vs. Anti-Fan: A Common Internet Mix-Up

Extreme violence against idols has also occurred, though it is crucial to differentiate the sources. Violence has often come from "anti-fans," a distinctly different phenomenon from sasaeng stalking. For instance, TVXQ member Yunho's famous 2006 hospitalization after drinking a beverage laced with superglue was the work of an anti-fan, though the incident is often incorrectly folded into sasaeng lore.

The Shifting Legal Landscape

Historically, protections against stalking in South Korea were weak. Before the introduction of a dedicated law, stalking was often handled under minor-offense provisions. This changed significantly when the South Korean government passed the Act on Punishment of Crime of Stalking in 2021. The Act created a specific criminal framework for repeated stalking and victim-protection measures. Current law provides for up to three years in prison or fines of up to 30 million won, with heavier penalties of up to five years in prison or 50 million won if the stalking offense is committed while carrying or using a weapon or other dangerous object.

Concurrently, major agencies including HYBE have increasingly adopted tougher responses. In 2023, HYBE formed a dedicated task force to track the illegal trading of artist flight information, formally submitting evidence to the police and calling for strict prosecution.

Ultimately, sasaeng behavior should not be treated as representative of K-pop fandom. What distinguishes some sasaeng activity from isolated stalking is the infrastructure around it: personal data, transport, and access can all become commodities. This market can make privacy violations easier to repeat even as enforcement becomes stronger. While enforcement tools are stronger than they were a decade ago, illegal data trading remains difficult to completely eliminate.