Just in case it still isn't clear that this is a co-located, news reading, automated market, here's the blast when the Greek bond swap participation level was released. The computer activity peaked at 14:52:12. At that time, 600 stocks had HFT Algorithmic sequences in them and simultaneously 850+ Stocks had HFT quotes. You'll notice the day ended at the level at which the computers entered in impressive size.
Here's the Raw Quote Bursts from HFT Alert Pro:
And the Quote Fluttering on VXX and DIA exchange traded funds on BATS exchange