Paperwork filed in a San Francisco federal court shows Facebook accusing BlackBerry of nicking its voice messaging technology, among other patented processes. Facebook wants cash for the infringement of six patents.

Facebook cites infringement of patented technology that improves how a mobile device delivers graphics, video and audio and another that centralizes tracking and analysis of GPS data.

All this appears to have kicked off after BlackBerry sued Facebook in federal court in Los Angeles, accusing the social media giant of infringing on its mobile messaging patents.

BlackBerry claimed Facebook made unauthorised use of its technology in its own instant messenger service, Facebook Messenger, and in WhatsApp Messenger and Instagram.

The former maker of mobile phones for the technologically challenged has been trying to raise more cash from its store of patents.