Consider the elderly that are investing for retirement, they find their way to the message boards for validation only to see false posts about "SEC Violations" and "Class action suits"... or the head of a "typical growing family", with children to put through college, who is monitoring a message board only to read posts by a "pack of 15 to 20 Bashers" (probably 5 or 6 under various alias's) posting continuous disinformation... what do you think these new investors will do? It's safer to not buy or even sell the stock, put the money back in the bank than to deal with all this whirl wind of "unsupported" negative chaff.
The Internet has lured a whole new class of investor into the market. A new investor is just that - New! This new investor, while learning the basics, is particularly vulnerable to the tactics of professional Bashers. New investors tend to lurk in the background of message boards, content to form independent opinions based on what they read with their own eyes. Very often, honest, intelligent and cautious people can easily be overcome by a well orchestrated propaganda effort.
You must always remember that their is a lot of money to be made in just the motion of a stock UP or DOWN it doesn't matter! And Bashers have money at risk just as you do. But they have the edge of fear, lies, and falsehoods to post while preying on the un-initiated. The average investor dose not have the edge of organized deception.
Recent revelations have indicated that even Market Makers (those charged with keeping the playing field level) have been involved in stock manipulation by Bashing on a stock message board. HAVE NO DOUBT THAT THIS IS A REAL THREAT!