The problem of eavesdropping dates back to the 1370s, according to one historian
When people live together in small communities, they can be a great source of comfort and support to each other — but they can also really get on each other’s nerves. Every community must figure out the best way to keep conflict to a minimum. In the late middle ages, English village courts tried to maintain equilibrium by imposing punishment for eavesdropping, scolding, and noctivagation (aimless night wandering), three offenses, as Marjorie McIntosh explains in her book Controlling Misbehaviour in England, 1370-1600, “often said in local records to be damaging to local harmony, goodwill, and peaceful relations between neighbors.”
The term “eavesdropping” originally came from Anglo-Saxon laws against building too close to the border of your land, lest the rain running off your roof, the yfesdrype or “eaves drip,” mess up your neighbor’s property. “Eavesdropper” became the word for a person who stands within range of the eaves drip — too close — in order to listen in on what was going on inside the house. This is quite literally how eavesdropping was done, such as in the case of one Agnes Nevell, who was described in 1517 as “a perturber of peace in her neighborhood in that she lies under the windows of Edward Node and hears all things being said there by said Edward.”
The Eavesdropper by Eugen von Blaas
Eavesdropping was best carried out under cover of darkness, hence the suspicion under which noctivagators, or “nightwalkers,” were held. Anyone found to be wandering round at night without a good reason was assumed to be eavesdropping, as was John Rexheth, who was reported in 1425 to be “listening at night and snooping into the secrets of his neighbors.”
The problem with eavesdropping wasn’t so much about notions of rights to privacy as about people who “perturbed the peace” by using the information they gained through eavesdropping to sow discord. Getting the goods on your neighbors might lead to scolding — verbally attacking, berating, stirring things up. Where eavesdropping might get you fined, the punishment for scolding could be much worse. Repeat scolders might get dunked in the water on the “cucking-stool” until they were thoroughly soaked and humiliated, or made to wear a “scold’s bridle,” an iron muzzle with a spiked gag to keep the tongue from moving.
Clearly, offenses like theft, adultery, and inflicting bodily harm merited more severe punishments than skulking around at night to spy on your neighbors in order to collect ammunition for verbal harangues, but “for a good two hundred years, beginning in the 1370s, the medieval cocktail of eavesdropping and tale-telling comprised about 8 percent of all social crimes.”