Abdel Aziz al-Khayer is a peaceful political activist born in 1951. In 1992, he was arrested by Syrian security forces, and was thrown in jail, where he spent 13 years of his life.
On September 20, 2012, while returning from an official trip to China, he and two of his colleagues (Maher Tahhan and Eyas Ayyash) were arrested, and his fate remains unknown.
It's noteworthy that he's one of the key founders of the National Coordination Committee in Syria.