Cold callers have long been torturing home owners through a variety of tactics; usually through silent or highly vocal #telephone calls or door to door calls. The #legal rumours are if you have a sign prominently displayed requesting no visits then it could be a criminal offence -in theory at least according to an #anonymous QC. It's unhelpful that there hasn't been a reported benchmark ruling and so the law is largely toothless and ignored by companies and #organisations as there are no specific lines, or if there were perhaps the said parties wouldn't care.
On the nuisance telephone call front a #broadband provider was fined £750,000 for making over 9,000 silent calls. Might make them think twice next time, or it might not- presumably there are two main reasons companies persist with cold calls just off the top of my head; either it is making them too much money to give up and adequately covers any fines and slaps on the wrists they may get legally, or because it's just so cheap to do and the chances of getting custom that way -however slim- outweigh the costs of being caught and punished.
At the front door you have a slightly different ball game; you are in your home and are interrupted. It is arguably the more invasive of the two but that isn't to say that cold phone calls aren't annoying.
Door to door cold calling also gives brilliant cover to criminals targeting people with distraction crimes, especially elderly or vulnerable people. You have bodge-it-and-run #builders or handymen who pressure people into instant payments or accepting quotes, sometimes aggressively which #surprise surprise always seems to be increasing every time they feel like showing up again. Charities, religious cults and insurance sales people are also darkening people's doorsteps. It's time to slam the door and hang up on cold calling.