Syria's security forces. Ghiyath Mattar, described as a key organizer of protests against al-Assad's regime, was killed after being arrested last Tuesday in the Damascus suburb of Darya, State Department spokeswoman Victoria Nuland said in a statement released Sunday. His brave commitment to confronting the regime's despicable violence with peaceful protest serves as an example for the Syrian people and for all those who suffer under the yoke of oppression, the statement said Mattar was arrested along with leading opposition activist Yahya Sharbaji and a number of other activists, Nuland said. Mattar was a symbol of what the Syrian revolution should be -- peaceful and nonviolent, said one of Mattar's friends. His death is an attack by the regime on peace. His attack is saying, We want to destroy the messengers of peace in Syria and the ideals and values they hold. His personality was perfectly built to take the role of a leader, said another man, a colleague of Mattar's. Everyone loved him and he had so many close friends and relatives. Both men asked not to be named for fear of retribution. On September 6, Mattar was with Sharbaji when he received a call from Sharbaji's brother saying he was injured and needed help, according to the friend. In reality, security forces had forced the brother to call Sharbaji. The operation led to the arrests, the friend said. Unrest has