5.06 Million Members at Risk; Seoul Facilities Corporation Enhances Security Systems

(C) Seoul Metropolitan Government

SEOUL – Authorities have launched a formal investigation following reports of a significant personal data leak involving Ttareungyi, Seoul’s widely used public bike-sharing service.

On January 30, the Seoul Facilities Corporation, which operates the service, confirmed that a large volume of member information stored in its database had been compromised. While the exact number of affected users is still being determined, the scale of the leak is expected to be massive, as the service boasted over 5.06 million cumulative members as of the end of 2025.

Scope of the Breach
When registering for Ttareungyi, users are required to provide their ID and phone number. Many users also provide optional information, including:

Date of Birth
Gender
Email Address
Weight (used for calorie calculation)
Timeline of the Investigation

The breach first came to light on January 27, when the Seoul Metropolitan Police Agency’s Cyber Investigation Unit notified the Corporation of suspicious activity. It is reported that the police discovered the leak while conducting a separate, unrelated criminal investigation. The Corporation officially announced the breach today, following the initial police tip-off.

Emergency Response
Independent of the police probe, the Seoul Facilities Corporation has filed reports with the Personal Information Protection Commission and the Korea Internet & Security Agency (KISA).

In response to the crisis, a joint emergency response center has been established with the Seoul Metropolitan Government to bolster the security infrastructure of the Ttareungyi mobile app and website.

"We are cooperating fully with the police investigation," a spokesperson for the Corporation stated. "We will implement necessary follow-up measures as quickly as possible based on the findings of the investigation."

How to Report Damages
Users who suspect their information has been misused or who wish to report related damages can contact the following channels:

Public Bicycle Operations Call Center: 1599-0120
Email: seoulbike@sisul.or.kr
Seoul Dasan Call Center: 02-120