All of it, there are a massive number of these in use. The tiny minority they might cause a problem with is vanishingly small and getting smaller every day.
The technology is supported by all the major companies, recommended by Humax, provided free by BT for users of their Youview service
The main complainers cause significant problems for other users of the RF spectrum in close proximity to other users.
Thankfully in a democracy, the majority prevails
I am going to add a rider to every post mentioning homeplugs in future about the inevitable post from you.
Face it there are millions in use, a tiny tiny minority cause problems, far less than finding a clear WiFi channel when all the close neighbours have WiFi routers.
Running cable is not practical for everyone, neither is wireless.
The technology is 100% legal and licensed, it's time you recognise technology changes, 4G will create far more problems than ever homeplugs will ever do, perhaps you ought to find a new soapbox
Face it you have totally lost the argument,
It is you that is talking rubbish and you know it. All Homeplug installations cause interference by the very fact that unscreened, unbalanced mains cabling is used to pipe RF around the house and the problem is getting worse, not better, every day with the latest high speed units.
BT supplied Homeplugs are removed rapidly by BT when Ofcom get a complaint and an alternative technology provided.
I assume you mean radio hams by the main complainers. They do not cause problems for other users, they would swiftly lose their licence if they did. All the hams I have met are very concerned about TVI and will go out of their way to help and provide filters even though the problem is poorly designed domestic equipment. Signals from the local taxi company can also swamp poor equipment. Sadly taxi companies are not so helpful.
Running cable is no more difficult or impractical than running aerial or satellite cables. The problem is laziness.
Being legal does not make it harmless. Tobacco and alcohol are both legal and they both cause immense harm. The best we can do is try to educate people to the problems, and the same applies to Homeplugs.
No one really knows what problems 4G will cause but al least there is a mechanism in place to solve them. No free filters on peoples aerials can solve Homeplug problems so the best solution is to not use them, especially when there are so much better ways of getting ethernet around the home.