A massive global social network announces an initiative to encourage its nearly one billion users to donate organs and body parts with just the click of a mouse. Millions of potential transplant recipients rejoice, but there is a dark side. For a young, newly engaged professional in Portland Oregon, that dark side arrives wearing a smile and designer suit during a chance encounter at a train station.What are the pitfalls and dangers of socially networking body parts? Should you OPT-OUT?