What do you think of the phenomena of stranger shaming?

A short summary:
http://www.thejournal.ie/readme/women-who-eat-on-tubes-stranger-shaming-social-media-1403346-Apr2014/

And one unfortunate example:
https://thedebrief.co.uk/news/opinion/faced-much-online-abuse-eating-train-m-now-afraid-eat-public/

I am interested particularly if you do partake in this, why you think it is ok and morally justifiable to do so and those of you that don't.