Summary: We tend to view communication using social media, online tools and web sites, IM, chat, SMS, and so literally. Messages have authors, what they seem to be saying is what they in fact mean to say, and so on. The reader is the interpreter of what's communicated. But the medium not only transmits and enables talk by capturing communication on web pages, in chat and IMs, in emails, blog posts, and comments. It also produces the author: as an appearance or effect of the medium. This is enough to go on in most cases, but it does have implications. We do not "exist" online any more than a Second Life avatar exists in the real world. These are media of production. Presence, talk, intent, motive, character, personality.... all these are manufactured by the social media that are their means of production. HCI and human factors research has a deep field of study in social media.
We rely on visible information to know the authority of the person with whom we're speaking. Police officers, doctors, teachers, lawyers, and other figures of authority tend to bear some resemblance to the cultural expectations established for that role. There's variation and personal style, of course, but the fact of the matter is that authority carries better when it's worn properly. Technology, as we know, often provides no suggestion, let alone guarantee, that an individual claiming to be this analyst or that insider is indeed who he claims to be. Insofar as we trust authority based on our experiences with it, the abuses facilitated by technologies might have serious consequences.