*Uninvited Guests* - Human Agency[1] vs Machine Agency.
I found this gem via a CHI paper. I think it covers a number of pitfalls that can be avoided by insuring that we're designing products that emphasize Human Agency. It also underscores how privacy (especially between the device owner and the device user) is critical.
Also consider if instead of grandchildren the devices were provided by the NHS or Medicare.
[1]
Ultimately it is our intention that this, at times comedic story, plays on and gives form to some of the growing tensions between human and machine agency. And in doing so, provoke questions about how we want to live and grow old in an increasingly technologically mediated word.