A debate over whether Google has the ability to glean children’s personal information from websites they visit took center stage during arguments before the U.S. Court of Appeals for the Third Circuit.

Lawyers representing children who visited the Nickelodeon network’s website argued Google had the ability to extrapolate the children’s identities from usernames, birthdates and gender information they provided to Nickelodeon’s parent company, Viacom, for use of the website. Google’s cookies, installed on the website, would take that information and combine it with additional data gathered from other Google services to pinpoint the children’s names and addresses, their lawyers argued. Cookies are small bits of data collected by websites to record browser activity.