Facebook used its apps to gather information about users and their friends, including some who had not signed up to the social network, reading their text messages, tracking their locations and accessing photos on their phones, a court case in California alleges.
The claims of what would amount to mass surveillance are part of a lawsuit brought against the company by the former startup Six4Three, listed in legal documents filed at the superior court in San Mateo as part of a court case that has been ongoing for more than two years.
A Facebook spokesperson said that Six4Three's "claims have no merit, and we will continue to defend ourselves vigorously". Facebook did not directly respond to questions about surveillance.
Documents filed in the court last week draw upon extensive confidential emails and messages between Facebook senior executives, which are currently sealed.