Experts say they are safe, but some worry smart meters are making them sick or are even spying on them.
The FCC approved the use of smart meters by utilities and said their risk was minimal.
Residents are blaming the devices for health problems or fires.
Some even claim their two-way communications ability allows utilities and the government to snoop.
Devised by utilities as a way to save energy, cut monthly bills and even reduce carbon emissions, "smart meters" that give more accurate data about a home's electricity use are facing a backlash in communities across the country.
Some residents are now blaming the devices for health problems or fires, and say their two-way communications ability will allow utilities and the government to snoop on them.
These fears have forced some states to allow people to "opt-out" of the smart meter program, which supporters say will actually make them less effective in the long-run to yield environmental benefits.
"If done right, smart meters allow us to eliminate waste from the system," said Jim Marston, vice president of energy for the Environmental Defense Fund, which supports the use of new smart meters.
"It's not unlike the revolution in telephones. These are things that allow you to know when you are gone and to turn off all your lights. Or to allow your appliances to turn on only when renewable power is available, or for utilities to figure out where outages are."
Marston and others say the devices will help lower overall energy use by giving customers more information about what kinds of appliances or behaviors are affecting the homes' utility bill. But the benefits will occur only if a large number of residential electrical customers use them.
Utilities in California have been rolling out smart meters for the past year and a half. They give hourly reports of electric usage through a wireless, or wired, connection. This stream of data allows utility managers to better forecast peak demand and plan for future supplies of power.
But there have been some hiccups.
The California Public Service Commission received thousands of complaints and has now given rate-payers until May 1 to drop out of the program and keep their older analog meters by paying a fee. Colorado, Maine and Arizona are allowing residents to opt out, while Maryland and the District of Columbia, are not.
Advocates like Joshua Hart say they worry about the long-term health effects of the radio frequencies emitted by the smart meters.
"You have a new source of involuntary exposure being put into people's homes and businesses," said Hart, who runs the group Stop Smart Meters from his home in Scott Valley, Calif.
"What we advocate for is informed consent. It's unfortunate for industry to have these devices installed without due diligence or adequate consultation."
Hart said there isn't enough known about the health effects of smart meters, which produce low levels of electromagnetic radiation. Hart compared the radiation from smart meters to that of cell phones.
In a review of health studies linking cell phone use to possible brain cancers, the World Health Organization concluded last year that "current evidence does not confirm the existence of any health consequences from exposure to low level electromagnetic fields. However, some gaps in knowledge about biological effects exist and need further research."
Public health officials point out that smart meters emit less radiation than cell phones -- and they're not used right next your head.
The Federal Communication Commission approved the use of smart meters by utilities and said their risk was minimal. Environmental health experts say the smart meters do not pose a serious health risk.
"As far as all the science suggests, (the risk) is not there," said George Gray, director of the Center for Risk Science and Public Health at George Washington University, and a former toxicologist at the U.S. Environmental Protection Agency. "It could be people drawing these inferences. I got a new pair of shoe and I got a cold, so the shoes gave me a cold."
One thing that Marston, Gray and Hall all agreed is that people some may be fighting against installation of these devices because they are mandatory, rather than optional -- and that utilities haven't done a great job of explaining the benefits to consumers.