This point of "scalability" however is important I think, because it addresses the issue of fixed representation more directly. How so? Well, current "social networking" tools basically force every person in the network to adapt to whatever categories are generally common. Furthermore, they force the parties in a relationship (implicitly) to agree on what their relationship is. I think it's not uncommon that you'd see a person as being, say, an acquaintance, and that person to view you as a friend (if not a close one). People don't always agree on what the relationship means to each other. This to me points to the need to let each person define their own relationship/trust structures and then let the software mesh them seamlessly if possible.