Strangely enough, I had never heard of a "darkpool" until today. I bought Flash Boys at the airport bookstore earlier, and read it on the plane just now. And tonight I find a reference to darkpools on the HN front-page. Hmmm. Truth really is stranger than fiction sometimes.
Anyway, FWIW, if anybody here hasn't read Flash Boys by Michael Lewis, it's a pretty interesting read that covers some ground related to the content of this article: HFT, dark-pools, etc. I understand that it's not without some controversy, but I found it damn interesting all the same.