Siri on the iPhone effectively provides access to all of the device owner’s data in an unrestricted fashion, albeit within the bounds of what Siri could be asked. As an iPhone is a personal device, there is relatively little in the way of concern about this, as the iPhone is almost always within easy access of its owner, who can limit Siri’s usage by others quite easily.
The same cannot be said for devices like the HomePod, which is designed to be used communally, with multiple people able to take control of playback by asking Siri.
