My cellphone

  

My cellphone automatically lights up every time I pick it up and look at it.  I thought it was triggered by the motion of picking it up, but then I realized I don't have to move the phone at all; if I wave my hand in front of it, not just anywhere but up by the camera, the face of the phone lights up.  A convenient feature because any time I pick it up, it's ready to use.

 

That suggests that the phone camera is on though, even when it's not on, so it can recognize when I have a need for the phone.  I guess the phone camera only works when I tell it to, or when the programmer tells it to.

 

There is nothing left to hide.