BlackBerry filed a patent infringement lawsuit against Facebook, claiming the social networking company’s WhatsApp and Instagram apps copied key BlackBerry Messenger technology and features, multiple media reports stated.

“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 filing with a US federal court in Los Angeles.

In response, Facebook deputy general counsel Paul Grewal said: “Having abandoned its efforts to innovate, Blackberry is now looking to tax the innovation of others. We intend to fight”.

“Blackberry’s suit sadly reflects the current state of its messaging business,” he added.

The case is part of a strategy announced by BlackBerry CEO John Chen in 2015 to use its patent portfolio to fund the company’s other activities, including its software and enterprise divisions.

BlackBerry is focusing on its core enterprise mobility software and continues to licence its portfolio of some 40,000 patents and applications covering technologies including wireless communications, networking infrastructure, messaging, operating systems and cybersecurity.

“Protecting shareholder assets and intellectual property is the job of every CEO,” a BlackBerry representative said in an email to Reuters.

The company said while this is not central to BlackBerry’s strategy, “we have a strong claim that Facebook has infringed on our intellectual property, and after several years of dialogue, we also have an obligation to our shareholders to pursue appropriate legal remedies”.

This move is the latest in many such cases BlackBerry is fighting. In February 2017 the company filed a patent infringement case against Nokia for using protected technology in its networking products. The case is still pending.

In May 2017, Qualcomm agreed to pay BlackBerry $940 million to settle an arbitration decision and in October BlackBerry settled a patent spat with handset maker Blu Products.