I don't think Apple has ever tried to hide this? - Stephan Planken

"“The iOS terms clearly state that Apple will record what you say and may send it to subsidiaries and their agents. It goes on to add that they will record the names of your contacts, your relationships with them, in-home devices, and sometimes your location,” writes Tim Pool. Where is the data collected by Siri being sent to? Last month, a Reddit user called called FallenMyst claimed that he had started work for a company called Walk N’ Talk Technologies and that his job was to check for incorrect translations made by Siri. Audio heard by the individual included “sexting via voice and people giving the usual banal and weird commands to their phones,” reported Forbes. As Pool points out, the vast majority of people don’t read terms of service agreements and so are completely clueless to the fact that Apple is recording their voice data and sending it to third parties, as well as keeping detailed records of their every location." - Sean McBride

My guess is that most users of Apple products haven't fully grasped the implications of this policy. - Sean McBride