An online tech blog posts a fake news item about a delay of a new Apple product. Story here Apple shares drop $6 - reducing companies overall value [temporarily of course] by $4 billion seeing how share price is partly determined by demand, and a bunch of investors got scared and sold out - raising availability, reducing relative demand & thus dropping the price. This is incredible though: a blog did this. A freakin' rumour Such is the power of the internet to distribute information quickly, effectively, and inaccurately by design if such is your want. Imagine if it was on purpose and someone sunk $20,000 into Apple shares when they hit their low after only 6 minutes. Selling them when everyone realised the story was fake and the market recovered would mean that person made $848 ... minus whatever $30 brokerage fee applies, that still ain't bad for a days work What if you had some real financial clout?... let's say a million bucks to invest? Well you just made $42,000 if you so choose to sell afterwards. Maybe you hang onto them. Maybe you launch a heavily discounted takeover bid for a controlling share in a company simply by asking your 15 year old nephew to write a crappy review of their product on his blog[?] I am impressed, surprised and a little purturbed by this. Almost confidence scheme-like tactics could be employed to profit from this. It doesn't matter how real a review is, or how discounted as 'fake' it can be, or how quickly that is done: as long as you scare enough people to make a difference. A Nigerian e-mail relies on producing hope in the foolish few. This market-scaring would rely on producing fear in the foolish few. ... and assuming such a review couldn't be traced back to you - or even if it was and you published it on a server in another country - would it be legal? Got my savings ready, time to call in a bomb-threat to the BHP Steelworks, I reckon.