ByteDance, the parent company of TikTok, admitted this week that several of its employees improperly accessed the data of American TikTok users and two journalists.

TikTok CEO Shou Chew acknowledged this in a memo published by the Bloomberg agency. The disclosure followed a months-long internal investigation at the company, which in turn was prompted by Forbes investigation. The latest claimed that the company planned to use the TikTok app to track the whereabouts of certain American users.

An investigation into ByteDance this week found that several employees accessed the identifying addresses and other personal data of two reporters for BuzzFeed News and the Financial Times, as well as an unknown number of American users with whom they were in contact. They reportedly tried to find out if these users were in close proximity to ByteDance employees. Their efforts proved futile.

“The misconduct of certain individuals, who are no longer employed at ByteDance, was an egregious misuse of their authority to obtain access to user data,” a company representative said. “This misbehavior is unacceptable, and not in line with our efforts across TikTok to earn the trust of our users. We take data security incredibly seriously, and we will continue to enhance our access protocols, which have already been significantly improved and hardened since this incident took place.”

ByteDance, as reports The New York Times, said it fired all four employees who had access to the data of American users. Two of them worked in China, and the other two in the United States.

After the investigation, ByteDance restructured its internal audit team and stripped the department of access to US user data.