An amateur is generally considered a person attached to a particular pursuit, study, or science, without formal training or pay. Conversely, an expert is generally considered a person with extensive knowledge, ability, and/or training in a particular area of study, while a professional is someone who also makes a living from it.
There is a problem according to Andrew Keen that amateurism through the internet is killing our culture, journalism, media and hurting our economy. People are also turning to the internet alot more for information because of acessability, which means that many are often subjected to unreliable information because of amateurs. It's just much easier to click on the mouse and bring up any information you choose to research or view.
Andrew Keen website http://andrewkeen.typepad.com/