Ars Technica:

In its complaint, Apple says that Qualcomm actually withheld $1 billion in payments it owes to Apple because Apple cooperated with the Korea Fair Trade Commission, or KFTC. Apple lawyers go on to make an extraordinary claim: that Qualcomm “attempted to extort Apple into changing its responses and providing false information to the KFTC in exchange for Qualcomm’s release of those payments to Apple,” but Apple refused.

Apple’s lawsuit seeks unspecified damages while stating it has been “overcharged billions” by Qualcomm. The lawsuit notes that law enforcement agencies around the world are investigating Qualcomm, which “has been declared a monopolist by three separate governments” in the past two years. Last month, Korean regulators slapped Qualcomm with a $850 million fine over its patent-licensing practices. The US Federal Trade Commission sued Qualcomm earlier this week, again over patent issues.

This feels like it might go beyond just the usual corporate lawsuits.