The document discusses social machines and outlines some of their key characteristics. It notes that social machines harness human participation on the web to solve problems at large scale. They augment both human intelligence and machines. However, social machines are not fully understood and are difficult to describe, classify, design, anticipate, and observe. The document also discusses how social machines form ecosystems and are not equivalent to Turing machines, as they evolve through interaction rather than having a fixed specification. It outlines some trends in social machines and examples of what they may accomplish in the future by coordinating huge numbers of people.