Re: BTC Vulnerability? (Massive Attack against BTC system. Is it really?)

What the OP described is called "cornering the market".  When someone tries to buy all the world's supply of a scarce asset, the more they buy the higher the price goes.  At some point, it gets too expensive for them to buy any more.  It's great for the people who owned it beforehand because they get to sell it to the corner at crazy high prices.  As the price keeps going up and up, some people keep holding out for yet higher prices and refuse to sell.

The Hunt brothers famously bankrupted themselves trying to corner the silver market in 1979:
"Brothers Nelson Bunker Hunt and Herbert Hunt attempted to corner the world silver markets in the late 1970s and early 1980s, at one stage holding the rights to more than half of the world's deliverable silver.[1] During Hunt's accumulation of the precious metal silver prices rose from $11 an ounce in September 1979 to nearly $50 an ounce in January 1980.[2] Silver prices ultimately collapsed to below $11 an ounce two months later,[2] much of the fall on a single day now known as Silver Thursday, due to changes made to exchange rules regarding the purchase of commodities on margin.[3]"

http://en.wikipedia.org/wiki/Cornering_the_market