Marketplace Tech is broadcasting from South By Southwest Interactive in Austin, Texas, this week. Two of the big themes are data and privacy. One of the big guests over the weekend addressed a sold-out crowd here from outside of the U.S. border. Julian Assange Skyped in from the Ecuadorian Embassy in London. Plus, a conversation with Guy Kawasaki the best-selling author who brought the first Macintosh to the masses in 1984.