On: Could The U.S. Gov't destroy Bitcoin by owning it all?

Wouldn't that just cause bitcoin to become more expensive, until it's so expensive the US can't afford to buy up the last few bitcoins?

By then the damage would be done, in fact I think they'd only need to corner the market w/ 60% or so to be able to wreak havoc on the stability of the system. Would be funny if this thread on HN led to the downfall of BTC by giving the gov't the very idea on how to destroy it.