By doing so, drillers have unlocked natural gas deposits across the East, South and Midwest that are large enough to supply the U.S. for decades. Natural gas prices have dipped to decade-low levels, reducing customer bills and prompting manufacturers who depend on the fuel to expand operations in the U.S.
Environmentalists worry that the fluid could leak into water supplies from cracked casings in wells. They are also concerned that wastewater from the process could contaminate water supplies if not properly treated or disposed of. And they worry the method allows too much methane, the main component of natural gas and an extraordinarily potent greenhouse gas, to escape.
Some want to ban the practice altogether, while others want tighter regulations.
The Environmental Protection Agency is studying the issue and may propose federal regulations. The industry prefers that states regulate the process.
Some states have banned it. A New York proposal to lift its ban drew about 40,000 public comments -- an unprecedented total -- inspired in part by slogans such as "Don't Frack With New York."
The drilling industry has generally spelled the word without a "K," using terms like "frac job" or "frac fluid."
Energy historian Daniel Yergin spells it "fraccing" in his book, "The Quest: Energy, Security and the Remaking of the Modern World." The glossary maintained by the oilfield services company Schlumberger includes only "frac" and "hydraulic fracturing."
The spelling of "fracking" began appearing in the media and in oil and gas company materials long before the process became controversial. It first was used in an Associated Press story in 1981. That same year, an oil and gas company called Velvet Exploration, based in British Columbia, issued a press release that detailed its plans to complete "fracking" a well.
The word was used in trade journals throughout the 1980s. In 1990, Commerce Secretary Robert Mosbacher announced U.S. oil engineers would travel to the Soviet Union to share drilling technology, including fracking.
The word does not appear in The Associated Press Stylebook, a guide for news organizations. David Minthorn, deputy standards editor at the AP, says there are tentative plans to include an entry in the 2012 edition.
He said the current standard is to avoid using the word except in direct quotes, and to instead use "hydraulic fracturing."
That won't stop activists -- sometimes called "fracktivists" -- from repeating the word as often as possible.
"It was created by the industry, and the industry is going to have to live with it," says the NRDC's Sinding.
Dave McCurdy, CEO of the American Gas Association, agrees, much to his dismay: "It's Madison Avenue hell," he says.