Congressmen from Nebraska sent a letter to EPA Director Lisa Jackson seeking an explanation after livestock operations in the state were monitored via aerial surveillance.

Republican Reps. Adrian Smith, Jeff Fortenberry and Lee Terry, as well as Democratic Sen. Ben Nelson and GOP Sen. Mike Johanns are concerned with privacy and other issues for the livestock operators and other landowners monitored by the agency.

“Farmers and ranchers in Nebraska pride themselves in the stewardship of our state’s natural resources,” wrote the Nebraska lawmakers in a release on Congressman Adrian Smith’s website. “As you might imagine, this practice has resulted in privacy concerns among our constituents and raises several questions.”