Obama's Drone Wars Undermine American Values - Campaign for Liberty: "n 2012 President Obama approved “signature strikes” in Yemen, a criteria for attack that is not based on actual or suspected wrongdoing, but rather on a vague set of behaviors that are said to be shared by militants.
This means that the individuals killed in the most recent drone attacks were not necessarily terrorists or even terrorist suspects. They were not proven to have committed any crime, nor were they proven to have been members of al-Qaeda or any terrorist organization."