Amateur-radio operators (hams) fear that power-line networking could spell an end to their private hobby and public service: The Wall Street Journal covers a debate that's been swirling for months, and starting to percolate out into broader media. Power-line networking encodes data over high-voltage power lines to distribution into homes, often requiring a relay (like a pole-mounted Wi-Fi device) from the pole to the house. This overlay is a hack, and hams are finding that the lack of design for this purpose in electrical wiring throws off heavy interference into their common bands.
The FCC has granted primary and secondary license status for many (all?) of the bands that hams use, which means that interferring uses have to be shut down. However, hams fear that the utility of the utilities' deployment will provoke new rulings, allotments, or legislation that will eventually disable their use.
The article notes that it's easy to prove interference in some areas, while in other tests, the deployment apparently causes no problems.