I go to pretty extensive lengths to keep my online and in-person identities separate. Not to cover myself for being a jerk, because I don't usually do that, but because my sexuality is not mainstream and I like to have a place to rant occasionally, and I'd rather not have those things coming up in a Google search run by a potential Employer or something. And compared to some of my friends, that's on the low end of the list of good reasons to maintain anonymity online.

In general, though, this reminds me of one of my favorite Heinlein quotes: "Moving parts in rubbing contact require lubrication to avoid excessive wear. Honorifics and formal politeness provide lubrication where people rub together. Often the very young, the untraveled, the naïve, the unsophisticated deplore these formalities as "empty," "meaningless," or "dishonest," and scorn to use them. No matter how "pure" their motives, they thereby throw sand into machinery that does not work too well at best."