The use of drones in modern warfare, where the person pulling the trigger spots their target on a video screen and is not even on the battlefield, has led some to question the ethics behind using such weapons.

The operation of the unmanned aircraft has dramatically increased under the Obama administration - a practice criticised by many nations including Pakistan and Afghanistan - particularly over the deaths of many civilians during attacks.

While the CIA and the White House contend that the use of drones is monitored, their details are usually kept secret, bringing into question the legality, transparency and accountability of US officials.

Al Jazeera's Scott Heidler reports from New York.