Re: @ Dwarf also
Cala does voice processing, as do all the rest (Siri, Alexa, Cortana), so there is no difference. All of them are listening and shipping it back to the mothership for processing.
Children use Xbox, iStuff, etc, so again it's the same argument.
It makes no difference the age of the consumer, since adults will have purchased all of them, even if they are subsequently given to children to use.