Are your questions to Siri and Cortana being transmitted to a third party?
In a Reddit post, FallenMyst explains that she works for a company called Walk N’ Talk Technologies where her job is to listen to these recordings and match it up with the text generated by the vocal inquiry to check for "incorrect interpretations." As part of her job, she is charged with generating feedback on how to improve Siri's understanding of the questions being asked by iOS users.
While we strongly suggest that you take this story with the proverbial grain of salt, Apple’s iOS Software License Agreement states that your voice data could be used "to provide and improve Siri, Dictation, and dictation functionality in other Apple products and services." Most iOS users gloss over the legalese when agreeing to any licensing agreement. Walk N' Talk supposedly also works with Cortana to improve the accuracy of Microsoft's personal assistant.
Even though this has not been confirmed, perhaps the safest thing that Siri and Cortana users can do is to watch what they say to the ol' gals and refrain from asking personal questions that you wouldn't want others to hear. According to FallenMyst, "Guys, I’m telling you, if you’ve said it to your phone, it’s been recorded…and there’s a damn good chance a third party is going to hear it." Just a few days ago, Samsung admitted that its Smart TVs can record things that you say in front of it and send the conversation to a third party.
Thanks for the tip!
source: Reddit via DigitalMunition