If your experience confined you to the virtual plains of the blogosphere, you could be forgiven for thinking that Andrew Keen was one of the most unpopular people on the planet. One blogger - on Keen's own website - recently described him as "a professional mental prostitute of the establishment". New media guru and Guardian columnist Jeff Jarvis has called him "a mastodon growling against the warm wind of change". Keen recently introduced himself on the Today programme as "the antichrist of Silicon Valley".

So what has he done? Find out here, and have your say below.