This is the crux of the problem in Smart metering. The last mile problem. The industry does not have standardized protocols or well tested technologies yet for power line communications.
Of the arguments voiced by the good hipp.. citizens of Marin County, the radio interference problem is a legitimate one, that even the power companies themselves struggle with. Its not that it messed up your wibe man but that the data throughput is unpredictable and there is no 'one-fit-for-all' technology that works in all environments, from city center to rural dwelling.
In simple terms, its all about bandwith and transmission theory. You can't expect to push a great amount of data realiably through wires made for electrical mains transmission, certainly not with any kind of high frequencies we are used to with our modern gadgets. The power companies have long used remote control modems at crawling speeds which use the overhead powerlines as transmission medium but those are pretty uniform in characteristics, and you only need to go from one grid node to the next with them. The last-mile end, the consumer end of the utilities are often a huge mess, with old and new wiring, switching and filtering all over the place. A bit like the POTS network was before telcos started tearing out their whole almost-last-mile infra and replacing it with fibers with DSLAMs at the end. The last mile can be anything from a mile to dozens of miles depending on where you are located on the city network. And although it doesn't take many bits of data to send this info down to the power company, you need to multiply that by the number of customers on a simple branch of the network which could be tens of thousands. even more. And every broadcast needs to be isolated from others. Think of collision zones on ethernet except you only have sub MHz bandwidth to work with and a crazy chaotic switching and transmission line characteristics.
Then there is also the very real problem of radio interference. Mains wires weren't designed or installed for carrying any kind of radio frequencies. Consequently it is all too easy to make them into nice ideal broadband antennas that radiate your signal into outer space. Many commercial PLC trials have stumbled upon this problem with local FCC's shutting them down for interfering with electrical appliances, control circuits other commercial radio systems. Furthermore, consumer appliances themselves increasingly interfere with anykind of PLC. Computers and TV's are pretty good sources of nasty radio noise flowing back to the utilities mains, but the worst culprit are all kinds of new compact fluorescent and LED lighting systems that use cheap crappy switching. Some of them are like plugging an electromagnetic countermeasures pod to your mains to make sure no data can get through!
The TFA mentions Hams (Amateur Radio Operators) as one of the opposing gangs and I can tell you that we don't take kindly to being bundled with bloody hippies! We tend to actually know WTF we are talking about! often alerting and advising the FCC and industry on how to best use the limited spectrum we all need to share. Hell, pretty much all the hams I know work for the industrial-complex: IT, telcos, utilities, defence...
73 OH3GPJ