British Telecom introduced a way of blocking unwanted sales calls called the Telephone Preference List (TPL) a few years before the Post Office introduced a similar service for unwanted circulars through the letterbox.
Now Neighbourhood Watch are introducing a similar scheme for door to door visitors, Spam visitors, if you will. Those unsolicited people that attempt to sell double glazing, shoe shine cloths, religion and electricity. New driveways, digital TV aerials, atheism and gas. Life insurance, carpeting, broadband and cleaning products.
"Spam Visitors, or Spivs, as I like to call them," said Head of Neighbourhood Watch, Curt Antwitch, "are a blight on our society. They turn up, usually while you're eating dinner, and try and keep you talking hoping that you're going to be polite and not just close the door."
People who have signed up to the Neighbourhood Watch scheme can call on the local neighbourhood annoying door-to-door blocker (or Ad-Blocker) should a Spiv come knocking.
"We have trained our ad-blockers well," said Antwitch. "They say things like 'there will be no sale here; and 'it would be a better use of your time if you were to attempt your pitch elsewhere', which is polite, but lets the Spiv know that there is no point them spending any longer at that door step."
Antwitch knows it's only a matter of time before the Spivs up their own game and fight back.
"We're now in an arms race," said Antwich. "I expect that we will need to train our Ad-Blockers in self defence before to long."