See: http://blockchain.info/pools

The "Unknown" miner had 9% last week, 11% a couple days ago, and 13% now. Even just 1% of the network is a huuuuge jump in hashrate.

To give a comparison, ASICminer has 19% of the share of the network and they actually are a corporation that reinvests their profits into making their own miners (a sure formula for insane growth).

Could this be a government attempting to destroy Bitcoin by dumping a few million into making their own ASICs? Or possibly a private actor trying to gain total control over BTC?

The rapid growth of this unknown miner is very concerning.