Lyft is investigating allegations that its employees misused customer information, the U.S. ride-hailing firm said on Thursday.

A current or former Lyft employee alleged in an anonymous online post that Lyft employees had tracked rides taken by their romantic partners and pulled information about celebrities such as Facebook CEO Mark Zuckerberg, according to tech news site The Information.

“The specific allegations in this post would be a violation of Lyft’s policies and a cause for termination,” the company said in an emailed statement to Reuters.

Customer data could be accessed only by teams that require it to do their jobs, Lyft added.