Apple has teams of human contractors listening to Siri recordings as part of the quality control measures for the service - and the Apple Watch is a large source of accidental recordings, potentially revealing some intimate details about the wearer.
According to a whistleblower talking anonymously to The Guardian, the aim is to improve the voice service, determine whether it was an accidental activation and if Siri provided an appropriate response.
The problem with the Apple Watch is that it can trigger a recording when it is lifted, expecting Siri to be used. The result is that the Apple Watch gets to hear a range of conversations it potentially shouldn't - consultations with doctors or sexual activity, for example.
These accidental recordings come about because the Apple Watch is being worn all the time and offers the Siri function - something to think about next time you're arranging your next dangerous liaison when wearing the watch.
"There have been countless instances of recordings featuring private discussions between doctors and patients, business deals, seemingly criminal dealings, sexual encounters and so on. These recordings are accompanied by user data showing location, contact details, and app data," reported the contractor.
The fact that Apple is using humans to interpret recording samples should come as no surprise: both Amazon and Google have recently been shown to be storing and using voice recordings to improve the service - but neither have the on-wrist presence that Apple Watch does.
Of course, all those working on Siri for Apple will have to adhere to the levels of confidentiality expected, but the contractor believes that human oversight should be more explicitly mentioned by Apple in its terms and conditions, because of some of the details that are being overheard.
Apple got in touch with Pocket-lint to say: "A small portion of Siri requests are analysed to improve Siri and dictation. User requests are not associated with the user's Apple ID. Siri responses are analysed in secure facilities and all reviewers are under the obligation to adhere to Apple's strict confidentiality requirements."
You can, of course, turn off Hey Siri on the Apple Watch or you can turn off the raise to speak functions in the menu of the Watch, which is an easy way to limit whether Watch is listening or not.