As regards interference with radio reception, I am not surprised that high speed data over unshielded powerlines causes problems. Blindingly obvious, imho.
I am more surprised that high speed data over unshielded phone lines, ie DSL, causes any fewer problems. Phone lines have the marginal benefit of being twisted, sometimes at least, which will help. But I remain surprised that all the extra spurious spectrum noise, from DSL, has gone largely uncriticised.