In a strange series of events, two children ages seven and 10 were told they were not allowed to talk about hydraulic fracturing, or fracking, under an oil company settlement reached by the kids' Pennsylvania family.

According to the AFP the 2011 settlement was unsealed last week. The plaintiffs Chris and Stephanie Hallowich as well as their two children were are bound by the agreement never to discuss the Marcellus shale basin or fracking, the report said.

Fracking, which blasts millions of gallons of water and chemicals to extract natural gas or oil from fractured rocks, has caused U.S. oil and gas production to skyrocket. The technique has been heavily criticized, and some environmentalists contend fracking contaminates groundwater.

The couple said that the shale gas drilling which was conducted near their house had caused serious health problems. The Hallowich’s received $750,000 in a settlement and in return were prevented from speaking about fracking.