This thread set off very loud alarm bells for me even before I got to Kheprera's post suggesting it was a no-no. She is right. This is not a good idea. I understand and acknowledge people's anger at NCSoft, but this crosses a legal line. I don't hold myself out as giving my fellow forumites legal advice, but as a friend, I advise you all: Don't do stuff that might potentially be a crime.
Hm. You seem to be correct on this being a no-no. The very last example is a "Bear raid," which is a deliberate attempt to drive down the price. That we're not trying to do it for financial gain or to initiate a take-over is irrelevant. So yeah, this is probably a bad direction to go.
Right. This would be collusion by multiple traders to drive down the price. I am not a specialist in SEC regulation or stock-related crime, but I know enough about their history to know this is the kind of action those laws were meant to curb.
The second part of Segev's post is the really important one. Many statutory crimes and nearly all civil legal penalties don't require that the person who gets charged have any particular motive in mind. Just wanting to manipulate the stock price is enough. The crime is the price manipulation and the conspiracy to do so. That is enough to get you either fined and censured by the SEC (civil penalties) or charged with a crime.
Pinballdave asked why this differs from A, B, and C getting "sour" on a stock and selling it at the same time. In that scenario, A, B, and C aren't getting together in a meeting, saying, "Let's all sell our stock in order to drive its price down." They're just deciding independently.
Again, this is not a good thing. Please protect yourselves and do not do this.