Esther Dyson argues about the high cost of brokering relationships. She is especially concerned about the power that might arise from companies owning 'social data' and managing it less properly. If the social software idea really takes of, her comparison with Google is not so far:

"For now, no one online social network has enough heft to matter. But these issues will inevitably arise when the services approach critical mass. Consider the undercurrents of discomfort already swirling around Google because it is perceived to control the content we see. Imagine a service that controls information about people, even if it only runs algorithms."

I agree with her - privacy has to be guaranteed. But on the other hand I do not consider it as such a major threat. People tend to argue long about privacy, but isn't it a simple equation? If the risk of opening yourself up to the community (by providing data about your ID) is bigger then the gain from 'leads or contacts out of the community' the system will fail. As social software has become much more accepted then some years ago, the gains apparently have been higher than the risk. According to my anecdotal evidence, most users are very educated nowadays and very aware of privacy while entering data on a website. But definitely an unauthorized use of data from one of the industry players, i.e. selling addresses to a marketing company in a situation of strong financial need, might cause a major blow to the industry.

Here is what Plaxo says:

"Plaxo believes that establishing trust with our users, both current and future, is essential to our success. We intend to earn trust one customer at a time by providing a valuable service, communicating openly and directly, and nurturing a customer-focused culture inside the company."

Another issue is the lack of industry standards. It leads to mails coming in and requesting you to enter your data in dozens of software tools can be very annoying. A standard like FOAF could be helpful. It is a bit complicated and hardly use as of now but open-source. I really wonder what happened to services like Microsoft Passport? Wouldn't it be useful to supply basic data in standard format (i.e. Passport or a "Plaxo API") or a web service connecting different social networks if needed?