"But it's also a side-effect of the web making it easy to construct social networks among people with minority interests; suddenly all sorts of stuff that was hidden back when it was just one person per 10,000 population town emerges as a 30,000-strong continental community. The 0.01% are no longer hidden, can no longer be marginalized. Never mind the 1% or the LGBT 10%."

This is completely off. We have seen first hand that knowledge of different types of people existing hasn't stopped marginalization and oppression, both on a personal and institutional basis. Just because groups of people can come together online for various subjects doesn't mean that society as a whole is more tolerant of those people. Legal prosecution and personal attacks continue for people regardless of how many others like them they can communicate with online.

What people will want to hide will remain of function of society at large, including the internet and how it affects perceptions.