BlackBerry sues Facebook over alleged messaging patent infringement

"Defendants created mobile messaging applications that co-opt BlackBerry's innovations, using a number of the innovative security, user interface, and functionality enhancing features," BlackBerry said in a California court filing seen by AppleInsider.

One specific example includes "Delivered" and "Read" receipts, now commonplace in messaging apps — including Apple's own Messages. Another asserted patent covers a dot with a number signifying how many unread messages a person has.

"BlackBerry's suit sadly reflects the current state of its messaging business," said Facebook's deputy general counsel Paul Grewal in statement. "Having abandoned its efforts to innovate, BlackBerry is now looking to tax the innovation of others. We intend to fight."

Once a monolith in the smartphone industry, Apple's iPhone and Google's Android platform have forced BlackBerry to turn to other means to stay afloat. Estimates suggest that just 850,000 BlackBerry-branded phones were sold last year, less than what Apple sold in one week during the last quarter. The company has abandoned its own BB10 operating system in favor of Android.

Current revenue streams include things like security software for self-driving cars, but also attempts to secure patent royalties. BlackBerry has over 40,000 patents, and has already sued firms like Nokia, Qualcomm, and Blu Products. The Nokia case is still pending, but 2017's Qualcomm suit was especially lucrative, resulting in a $940 million settlement.