I posted this one already but I think it works here too.
This is from Greg Maxwell author of the complete chondro.
"As the number of forums grew, and teh popularity of the most active forums increased, moderation became a problem. Self-styled "experts" with little to no experience or results jockeyed for attention and juveniles with no apparent education about grammar or punctuation used the boards for daily playgrounds. As many people know, the biggest problem with the Internet is that anybody can say literally anything. If knowledgeable and experienced people don't correct errors and keep things on track, then bad information spreads rapidly and confusion abounds. If these people do stand up and speak, those corrected can become openly hostile, and if forum moderators don't control this then good forums can be quickly ruined. At one point the, the strife became so bad that KS shut down all of its forums for a brief period. More than one forum was left closed, but those that remained open continued to allow a "free for all" atmosphere. Those who were intent on having intelligent discussions grew more and more frustrated with the situation, and most serious users got fed up and left. Unfortunately, human nature being what it is, this situation is doomed to be repeated anywhere mature and qualified moderators are not actively involved with Internet forms."