The famous teen pump-and-dumper Jonathan Lebed used Yahoo message boards exclusively back in the late 90s. Every morning before school he'd create a bunch of new Yahoo IDs (he kept getting banned) and pump the penny stock he had chosen.
Knowing such people lurked there ought to tell you something.
Getting off topic here, but I remember the SEC went full guns blazing after this kid while ignoring much bigger financial targets. The moral of the story is that you can get away with pretty much anything if you are a financial institution (in the worst case you might have to pay a small fine years later), but if you are a rinky-dink individual, look out.