I agree that this is a deeply divisive and compelling issue, but I don't think that online identity can be reduced to this binary polarity.
The very idea of personal identity is an extraordinarily complex and cloudy concept, and how we interact online has evolved utterly beyond recognition since the dial up days of my childhood. So your digital footprint isn't really a definitive thing; and I think it will be something completely different in a few years...
Mark Zuckerburg might be the paragon of transparency ("They trust me — dumb fucks..."), but this argument totally ignores who controls your information/identity. Of course Zuckerberg promotes voluntary transparency because Facebook controls and sells your information. And Wikileaks and other anonymous whistleblowers are often the only reason that governments and corporations are forced to be transparent. Despite your personal opinions about methodology (i.e.4chan might be Anonymous, but hardly represents the ideal of anonymity), transparency is often only ultimately possible through the condition of a less powerful critic's anonymity.
Therefore, transparency doesn't quite conflict or oppose anonymity, but I think this discussion about privacy and the power over information is just beginning...