Ron Hilliard came home from church one Sunday to find hundreds of plastic $5, $10, $20 and $100 bills hanging on his fence in Flower Mound, another message from townsfolk angry at him for signing a natural gas drilling lease for his suburban Dallas property.

In Damascus, Pa., about 1,500 miles away, drilling advocate Marian Schweighofer found the word "LORAX" — from the Dr. Seuss book about environmental destruction — spray-painted on the road near her family's farm.

Hilliard and Schweighofer have never met, yet both are living with the nastiness and rancor erupting in communities nationwide over the volatile issue of hydraulic fracturing, or fracking.

This technique allows stores of gas to be extracted from once out-of-reach, dense shale formations more than a mile underground. Intense drilling activity is under way in the Barnett Shale of Texas, the Marcellus Shale of Pennsylvania, and other shale regions around the country.

This energy boom has turned neighbor against neighbor.

One side touts the jobs and prosperity drilling brings, allowing businesses to grow and farmers to hang on to their land. Gas leases have made millionaires of some property owners.

On the other side are those who either won't gain anything or believe the wealth isn't worth the risk. Alarmed by toxic spills, scattered drill site explosions and tainted drinking water, they fear a reduced quality of life and declining property values.

"Those who own their mineral rights are happier than a pig in mud," said Flower Mound resident Chris Tomlinson, who is making thousands of dollars a month from gas wells on his land. "Those who don't, want it to go away."

The acrimony is unlikely to subside soon. Even with about 26,000 wells drilled in 16 states through the end of 2009 — more than half of those in Texas — the shale gas revolution is still relatively young.

Most of the wells have been drilled in the past decade, particularly in Pennsylvania's Marcellus Shale region and in Texas' Barnett Shale, where the new extraction techniques were perfected and the boom began in 2006. Hundreds of thousands more wells could be drilled in coming decades, according to companies and energy officials.