Protecting intellectual property is one way Canada-based BlackBerry Limited aims to continue making money after effectively pulling out of the mobile phone manufacturing business. That means negotiating patent licensing deals behind closed doors, as well as forcing profitable settlements and waging legal war against some of today’s most powerful tech companies.

Facebook is the latest high-profile target of an extensive litigation effort, as BlackBerry points the finger at the world’s largest social network for allegedly “co-opting” BBM innovations without permission.

BBM, known formally as BlackBerry Messenger, was pretty much the precursor of instant messaging apps like WhatsApp, launching in 2005 and reaching peak popularity just a couple of years later.

Facebook and Facebook-owned services WhatsApp and Instagram are now accused of “using a number of the innovative security, user interface, and functionality enhancing features that made BlackBerry’s products such a critical and commercial success in the first place.”

Of course, many of the “innovative” features in question feel way too broad and generic to prove a direct correlation, not to mention premeditation by Mark Zuckerberg’s social media giant to unlawfully appropriate patented technologies.

But BlackBerry seems to be throwing everything it has at Facebook, filing a formal complaint of no less than 117 pages. For its part, the accused is adamant it never directly or indirectly committed copyright infringement of any sort, pointing the finger back at the accuser for “looking to tax the innovation of others” after abandoning its own “efforts to innovate.”

Buckle up, ladies and gents, it sounds like we may be in for quite a drawn-out, no-holds-barred judicial dispute.