If you look at social networks (Facebook, twitter, LinkedIn, etc.), you will see that they are usually based on relationships between individuals and on occasion (corporations). These relationships are based on individuals with common characteristics and are purely voluntary. Individuals represent themselves. They can act as experts on various topics or provide advice.
Usually relationships in social networks are very loose. Involved users don't have to use their real name and may join and leave the network as they please without experiencing any real penalties. Although certain behavior is frowned upon, the worse that can happen is that their account for that network is deleted.
There are, however, a variety of other types of relationships in which we as individuals are involved. For example, a user may represent his corporation when collaborating with other individuals from other corporations. In such a relationship, there are certain legal requirements that must be met in order for such collaboration to even take place. There are governance issues. Before such individuals can interact, there must be legal agreements that must be present - or there must be some common agreement regarding which rules (moral, etc.) are valid and which must be followed. In a collaborative project environment in which individuals work together, there will be a big difference between environments in which individuals can come and go as they wish (such as open source development projects) and situations where individuals have a certain responsibility (regarding commitment of time and materials) that must be met.
This idea isn't just restricted to corporate cooperation. What about a social network from a clinic that is based on group therapy between an experienced therapist and a group of out-clinic patients. If the group understands that the therapist is obligated by his legal responsibility to not pass the discussed information on to others, the patients may be more willing to speak freely. Thus, such a "closed" group bounded by a legal document / responsibility might be much more effective than a normal chat room.
What effects can different relationship characteristics have on social network technology? One impact may be linked to admittance to the social network itself or to certain parts of the social network. For example, in order to join certain groups, users are required to provide certain legal documents that act as a "governance gate" and which spell out the restrictions and expectations of joining the network.
Thus, it can be expected that as social networks on the Internet expand in their popularity than such networks will expand to include other types of relationships. The technology involved must also change to meet these new restrictions. For example, interaction with other systems (for example archives from notary publics or attorneys) where the presence of documents may be checked. Another possible scenario involves the use of other authentication schemes (besides username/password) where the real identification of users (perhaps via PKI or other stronger methods of authentication) is known.
Currently, this necessary changes in existing social network software is usually the result of custom development work. There is definitely potential here for niche players to move into this area.