I wouldn't be so quick to admonish the idea. Neighbours aren't always within talking distance. Even the writers of this article needed to create a WhatApp group, and you can already see the trouble in that. People want to receive messages about things in their neighbourhood, but groups chats cover fixed areas so some people might be on the "edge" of multiple groups. The logical solution here is a digital version of the old church notice boards you see in many towns, allowing people to place and view digital flyers in a certain range of their location.