The second International Drone Summit is taking place this weekend in Washington, D.C. Relatives of those killed by U.S. drones in Pakistan and Yemen are gathering with drone critics from CodePink and other organizations. Among those traveling from Yemen is Faisal bin Ali Jaber, an engineer whose nephew and brother-in-law were killed in a drone strike. In a letter to President Obama, Jaber said his nephew was a policeman while his brother-in-law was an imam who preached against al-Qaeda. He wrote, “In his death you lost a potential ally — in fact, because word of the killing spread immediately through the region, I fear you have lost thousands.”