With the flick of a switch, they can deploy this technology to a global scale and way beyond protecting children. Imagine the feature propagating to their Chrome browser or their smart speakers "listening in" on what's happening in your home to "prevent" crimes by sending the cops whenever you raise your voice or say "the wrong things." This kind of power should not be in the hands of a single company.
Unfortunately prisons, which are increasingly private for-profit enterprises, will continue to exist. Think about it: if you're banned from google, how will your body continue to generate revenue?
Reminds me of another "Social Media Corp Gone Bizarrely Crazy" plot that I read recently, The This, by Adam Roberts. You won't anticipate how Crazy the social corp in question goes till you're halfway.