This story from Slate tells about the suicide of a young girl after her father shaved off her hair in an act of public shaming.
Public shaming online is a particularly awful trend that is the 21st-century equivalent of the parent who makes a big production of whipping their kid in public (not that that's gone away). The parents might be thinking, "Look how terrible my child is and how hard I'm not putting up with it." But I actually think, "The real shame lies with who's taking the picture."
Online shaming has very real (and sometimes tragic) consequences. It can destroy relationships between parents and children. It often overrides the magnitude of the transgression, assuming there's even a real transgression. And, again, it says more about the mindset of the shamer than the shamee. What it says is not good. So knock it off and deal with such conflicts in private, where they can solved and not linger in photo form forever.
As for pet shaming, that's just ... weird.