Sending and receiving mail used to be a very public affair. Senders had to take their letters in person to a receiver at a Receiving House or to a Turnpike House where their mail waited to be picked up by the Royal Mail coach. Receiving a letter was the same procedure in reverse. Who was posting or receiving mail was public knowledge.
When the first pillar boxes were introduced in Britain from mainland Europe in the 1850s, the instinctive reaction of many was one of concern. Concern because now there was a way in which letters could be sent anonymously by slipping them into the now iconic red pillar boxes. The contemporaneous introduction of the Uniform Penny Post, complete with postman deliveries, ensured that receiving mail became a simplified and private business too.
Many worried about the consequences of such postal reforms: The public would begin to send letters anonymously and cheaply and nobody would know who was writing to whom and for what mischievous purpose. To many, this clearly marked the beginning of the end of Victorian moral rectitude and heralded the breakdown of civilised society.
Needless to say, despite the unfounded initial concerns, the ensuing revolution in interpersonal communication heralded, not the collapse of civilisation, but the dawn of a new era of democratised transmission of information.
Many thanks to wasabicube for his picture.