"Their presence terrorizes men, women, and children, giving rise to anxiety and psychological trauma among civilian communities. Those living under drones have to face the constant worry that a deadly strike may be fired at any moment, and the knowledge that they are powerless to protect themselves.

"These fears have affected behavior. The U.S. practice of striking one area multiple times, and evidence that it has killed rescuers, makes both community members and humanitarian workers afraid or unwilling to assist injured victims."

The study goes on to say: "Publicly available evidence that the strikes have made the U.S. safer overall is ambiguous at best … The number of 'high-level' militants killed as a percentage of total casualties is extremely low - estimated at just 2% [of deaths]. Evidence suggests that U.S. strikes have facilitated recruitment to violent non-state armed groups, and motivated further violent attacks … One major study shows that 74% of Pakistanis now consider the U.S. an enemy."

"U.S. targeted killings and drone strike practices undermine respect for the rule of law and international legal protections and may set dangerous precedents," the report says, questioning whether Pakistan has given consent for the attacks.

"U.S. practices may also facilitate recourse to lethal force around the globe by establishing dangerous precedents for other governments. As drone manufacturers and officials successfully reduce export control barriers, and as more countries develop lethal drone technologies, these risks increase."

The report supports the call by Ben Emmerson QC, the UN's special rapporteur on countering terrorism, for independent investigations into deaths from drone strikes and demands the release of the U.S. department of justice memorandums outlining the legal basis for U.S. targeted killings in Pakistan.

Fears that U.S. agents pay informers to attach electronic tags to the homes of suspected militants in Pakistan haunt the tribal districts, according to the study. "[In] Waziristan … residents are gripped by rumors that paid CIA informants have been planting tiny silicon-chip homing devices that draw the drones. The Guardian

The CIA and the U.S. military have used unmanned aerial vehicles known as drones to target and kill those Washington calls “suspected militants” in Pakistan, Afghanistan, Iraq, Yemen, Somalia and Libya.

In 2008, after Barack Obama won the presidency in the U.S., the drone strikes escalated and soon began occurring almost weekly, later nearly daily, and so became a permanent feature of life for those living in the tribal borderlands of northern Pakistan, according to CBS News.

A report released by the United Nations in June 2010 called the drone attacks part of a "strongly asserted but ill-defined license to kill without accountability."

The American Civil Liberties Union (ACLU) has taken the CIA to court in an attempt to get the agency to hand over documents related to President Obama's controversial "targeted killing" program that uses drones to take out suspected militants.

The ACLU says the CIA’s refusal to confirm or deny that it has records on the drone program is unlawful because President Obama and Defense Secretary Leon Panetta have publicly acknowledged the program’s existence in public interviews.

Local sources say more than 2,800 civilians have died in the drone attacks since 2004.