A civic group filed a complaint against Kakao with the privacy watchdog on Monday, alleging that the tech giant's corporate advertising service uses personal data to target users without their consent. The Seoul YMCA said it urged the Personal Information Protection Commission (PIPC) to investigate KakaoTalk’s Brand Message service and impose strict sanctions if violations are confirmed. The group said Kakao replaced its previous channel-based advertising service, which limited promotional messages to users who had added a business’s KakaoTalk channel, with Brand Message, which allows businesses to send ads without requiring users to follow their channels. It alleged that Kakao matches phone numbers provided by advertisers with its own user database to identify ad recipients, even though users had provided their numbers for basic messaging functions, not to receive third-party advertising. “The key alleged violations involve the unauthorized use of personal information and infringement of users’ rights,” the group said. “Although users agreed to provide their phone numbers for