The SEC states:
Bulletin Boards
"Online bulletin boards – whether newsgroups, usenet, or web-based bulletin boards – have become an increasingly popular forum for investors to share information. Bulletin boards typically feature "threads" made up of numerous messages on various investment opportunities.
While some messages may be true, many turn out to be bogus – or even scams. Fraudsters often pump up a company or pretend to reveal "inside" information about upcoming announcements, new products, or lucrative contracts.
Also, you never know for certain who you're dealing with – or whether they're credible – because many bulletin boards allow users to hide their identity behind multiple aliases. People claiming to be unbiased observers who've carefully researched the company may actually be company insiders, large shareholders, or paid promoters. A single person can easily create the illusion of widespread interest in a small, thinly-traded stock by posting a series of messages under various aliases."
Source: U.S. Securities and Exchange Commission
cyberfraud.htm
Market Data 
Markets 
