Two law professors told Democracy Now on Wednesday that the use of targeted drone strikes in rural Pakistan had terrorized the local population.

Stanford professor James Cavallaro and New York University professor Sarah Knuckey travelled to Pakistan to study the effects the drone strikes had on civilians.

"What we found, much to our surprise, was, first of all, that there is significant evidence of civilian casualties," Knuckey said. "Most reliable evidence indicates between 400 and 800 civilian casualties since 2004. Second, that more than the deaths and injuries to civilians, there’s broad mental health impacts for people. They are unable to protect themselves from the drones, which fly 24 hours a day."

Drones operated by the U.S. have been used to kill suspected terrorists in Afghanistan, Pakistan, Yemen and Somalia. While the drone campaign has killed top leaders of Al Qaeda, the practice has received criticism from human rights advocates.

Cavallaro added that the constant drone strikes had caused people in Pakistan to live in fear, causing significant societal and psychological effects. He said that people were afraid to congregate in groups or attend funerals, which are sometimes targeted.

"In short, there’s a breakdown in basic social engagement that we’ve documented, and what it adds up to is thousands of people living in a region where drones cause them to experience life as though they were in a war zone," Cavallaro said. "And the last time I checked, the United States had not declared war on Pakistan."

Watch video, courtesy of Democracy Now, below: