First, if you haven't done so, watch this excellent short film by Kate Ray, which looks at the concept of the semantic web and interviews leading thinkers in the field such as Tim Berners-Lee, Clay Shirky, etc:
I guess the next question that arises from this is, and to me the one that most closely associates with my own interests and the profession of librarians: do people have anywhere near the information and privacy literacy skills to understand these issues and the possible consequences of not paying attention to the security and privacy of their own information and information habits? Do they even have the skills necessary today? I would argue no, and that for any kind of significant semantic web concept to succeed, that literacy piece needs to be addressed in a serious way.
What say you?