Qualcomm, not surprisingly, disagrees with the decision. It plans to call for a stay on "any required behavioral measures" and will appeal the FTC's action in Taiwanese courts. The fine has "no rational relationship" to Qualcomm's actual revenues in Taiwan, the company said.

The fine comes on top of an existing $854 million fine in South Korea, a $975 million fine in China as well as lawsuits from Apple and the FTC. While Qualcomm can likely handle the financial penalties, it's the crackdown on behavior that will likely give it the most grief. It has regularly accused phone makers and others of refusing to pay what it expects for patent licenses, and the antitrust actions could easily force it to accept far less favorable terms. And when Taiwan is one of the world's more important cellphone markets (it's the home base for firms like ASUS and HTC), Qualcomm doesn't have much choice but to play along.