Consumer electronic devices like TVs will be networked simply by plugging them into the mains, if Panasonic has its way. The company has confirmed my rather rushed story from Friday, which followed the release of its data-over-the-mains kit into the UK.

It is working on implementing the technology at the circuit-board level of TVs and other devices, which will be launched first into Japan. The idea is wonderful, if only it would work. No messing about with Wifi, Ethernet jacks. or even mains Ethernet adapters. If a device is on, it will talk to its neighbours.

There are a number of caveats. Mains data is susceptible to interference from appliances like washing machines. And plug-and-play networks need standards: Panasonic is using a proprietary technology and so unless this is adopted by other consumer electronics companies it will only work with the company's own equipment.

Yet giants like Samsung, LG, Sharp and Sony belong to the Home Plug Powerline Alliance, which has a rival technology.

Then there are the concerns over mains data itself, which in radio terms is filthy: power leads were not designed to carry high-frequency signals and they act as transmitting aerials.  Companies assure us that frequencies that might cause problems are 'notched out' and that the RF levels are too low to cause problems. But I am not convinced that anyone knows what the cumulative effects will be of millions of homes in a city using the technology.

At the very least it will raise the noise floor. And even low-power short-wave signals can cross continents because they bounce back from the ionosphere, which is how radio hams get to talk to the world. A capricious burst at a certain frequency in London could conceivably jam ambulance communications in Cape Town.

We are already suffering from Wifi noise. I don't think I have set up a Wifi link recently where there have been fewer than five installations within range; you can't have more than three 11b/g setups near each other without some contention. Yet the industry is talking about pumping up the range of Wifi and using it to shunt around HDTV. Is it really going to scale up?

My pet idea is to stick fibre into mains cable and network new houses at the time you wire them up. With 300,000 news homes due to be put up in Britain alone there would be plenty of incentive to develop foolproof interconnects and train people to install them.