Andrew Keen is probably one of the best known techno-pessimists and his services as a speaker are in high demand.
[I used to work with Mr Keen at Podtech where I was helping develop a range of tech-related video shows.]
Mr Keen has spent many years lamenting the fall in quality of our culture because of amateurs rewriting our encyclopedias (Wikipedia) and competing with high quality TV (Youtube videos of skateboarding cats) and the decline of professional journalists and editors (and the rise of blogs).