Chesapeake Energy Corp,the Oklahoma-based firm is the No. 1 driller in Ohio.
Rig Count Interactive Map by Baker Hughes, an energy services company.
Shale Sheet Fracking, a Youngstown Vindicator blog.
The Ohio Environmental Council, a statewide eco-group based in Columbus.
Earthjustice, a national eco-group.
People's Oil and Gas Collaborative-Ohio, a grass-roots group in Northeast Ohio.
Concerned Citizens of Medina County, a grass-roots group.
No Frack Ohio, a Columbus-based grass-roots group.
Fracking: Gas Drilling's Environmental Threat by ProPublica, an online journalism site.
Pipeline, blog from Pittsburgh Post-Gazette on Marcellus shale drilling.
Allegheny Front, environmental public radio for Western Pennsylvania.
The U.S. Department of Homeland Security has identified a series of cyber attacks targeting natural gas companies in recent months, raising a red flag over potential threats to the nation's infrastructure, Fox News reported today.
The agency's Industrial Control Systems Cyber Emergency Response Team said in its latest monthly report that it uncovered "an active series of cyber intrusions targeting natural gas pipeline sector companies."
It was not immediately clear whether the attacks were aimed at the actual pipeline network or the broader companies operating in the sector, Fox News said.
The government agency said it was working with the industry to assess the threat.
It did not offer any more details on the source of the threat.
It said it was working witht he FBI and other federal agencies in the investigation.