Facebook sues BlackBerry, claims it stole voice-messaging tech
The suit comes months after BlackBerry sued the social network over mobile messaging tech.

Facebook accused BlackBerry of infringing on six of its patents.
Facebook hit BlackBerry with a lawsuit Tuesday, claiming the company stole its voice-messaging technology and other patented processes.
The social media giant accused BlackBerry of infringing on six patents in a complaint filed in San Francisco federal court, Bloomberg reports.
Beyond the voice-messaging patent, Facebook says the Canadian business software provider and one-time phone giant infringed on tech used to improve how mobile devices deliver graphics, video and audio and another used to centralize GPS data tracking and analysis.
Neither Facebook nor BlackBerry immediately responded to requests for comment.
BlackBerry sued Facebook in March, saying the company infringed on its mobile messaging tech for its own Messenger, as well as its Instagram photo sharing app and WhatsApp messaging service.
It said that suit came after "several years of dialogue" with the social network.