20 years is just a SWAG for when computational resources will be so abundant that the scariest level of analysis will be routine. Today it's simply not practica

20 years is just a SWAG for when computational resources will be so abundant that the scariest level of analysis will be routine. Today it's simply not practical to determine automatically everyone appearing in a given random photo or video. Facebook vastly simplifies the problem (by narrowing the search scope tremendously), but there's a lot of content elsewhere. For example, consider identifying people by the way they walk, the clothes they tend to wear, their body build, etc. That sort of thing makes witness protection efforts practically useless, for example. The sheer amount and detail of information that could become available will enable things that we can't even remotely imagine today, but ultimately the biggest change will be loss of anonymity at every level and loss of privacy.