Swiss privacy software company Proton on Monday sued Apple in U.S. federal court, accusing the technology giant of maintaining an illegal stranglehold on iPhone app distribution and charging excessive commissions to app developers.

Apple last week announced an insanely complex set of changes to its App Store terms in the EU, and hidden in the small–print is one sign that the company might be reducing its standard commission from 30% to 20%, and that it may make this change globally.

Apple has revamped its app store policies in the European Union with hopes of fending off escalating fines under the 27-nation bloc's digital competition regulations. It's a last-minute bid by the iPhone maker to avoid further charges following a 500 million euro ($585 million) penalty in April.