South Korea fines Bithumb for sharing user data overseas without consent

South Korean authorities have ordered Bithumb to pay a 210 million Korean won ($136,000) penalty for sharing its users' personal information with overseas platforms without consent.

According to a Thursday announcement, South Korea's Personal Information Protection Commission (PIPC) said the exposure of user information occurred when Bithumb shared its Tether USDT market order books between September and November 2025.

Although Bithumb obtained user consent to transfer information to Stellar exchange, the data was actually shared with a platform operated by BingX, according to the PIPC.

The PIPC also noted that Bithumb failed to obtain full user consent when it shared users' names, wallet addresses, and dates of birth while facilitating transfers with 13 overseas exchanges.

Following the two violations, the PIPC ordered Bithumb to rectify its protocol for transmitting user information overseas, alongside the penalty.

"The PIPC determined that the cross-border transfer of personal information is a matter closely related to the data subject's right to self-determination, and therefore requires meticulous compliance with the requirements and procedures stipulated in the Personal Information Protection Act," the commission wrote.

The watchdog also published an information protection guideline tailored to blockchain firms, taking into account the technology's transparent, distributed, and immutable nature. The guideline stipulates that information capable of identifying an individual, such as names and social security numbers, should not be recorded onchain.