Me too, is guilty of sending apps for review, timebombed to change their behavior after review is passed. This is how numerous vintage game console emulators got into appstore disguised as harmless utilities like flashlights. Apple can't do much about it, because it's an arms race they can't possibly win.This is concerning and a little bit curious. How can such apps pass the supposedly stringent review processes? Interesting development indeed.
However, developer program license agreement clearly states what is forbidden for apps to do, and review pass doesn't relieve developers of any responsibilities or consequences (of being banned from Apple's AppStores for a lifetime).
As for sneaky bastards in question, i bet they can afford to bribe a random homeless person into buy a 99$ developer subscription for them.