I remember reading a quite in-depth article about this. The carriers intended for BPL WILL cause interference with short wave radios. There is a wide spread concern that the emergency radio bands were due to become engulfed by the noise floor being raised so far that you would need a power station to transmit a signal strong enough. The Tsunami that hit Asia and Africa recently highlighted the need for sanctions to be put in place to protect the short wave radio bands. Immediately after the tsunami, news spread very fast due to the use of small short wave radios. They were the most important piece of equipment in the aftermath because there was no other way of communicating over the vast distances involved. BT are currently working on a system that confines the emitted noise to frequencies that are not suitable for long distance communication. As you know the optimum carrier for short wave radio varies throughout the day, BT plan to have what has been dubbed "ionosphere watch" to make sure their power line noise does not interfere with the vital emergency short wave radio bands. Another advocate of sanctions against such noise being allowed is the BBC. Strange? maybe not if you consider that the "World Service", listened to by millions of people across the world, uses short wave radio. Rest assured, there are plenty of people doing real work to preserve short wave radio, The only real problem is the situation in America, last thing I heard was something like the service providers didn't really care and are going ahead regardless. Short wave radio does not play a large role in the every day lives of Americans, 'so that means that no one in the whole world needs it'. Like carbon emissions, America doesn't really care that it's actions affect the whole world.