The major problems with the book fall into 3 major categories:
A) He implies (but never proves) that HFT market makers use low latency connections, to buy shares ahead of other market participants, to sell back to them risk free. This is not how HFT market making works. HFT market makers are pricing on all the exchanges at the same time. So what they are doing is not buying something and selling it back to you risk free, but changing the price of their own offering to reflect new demand.
B) That any of this is secret or requires insider information. It is all available on public websites, including governmental agency ones (for instance all "exotic" order types go through a public approval process). Further, in the book the only proof of ill gotten proprietary information being used for profit was from the supposed "heroes" of the story.
C) That HFT is a large force that abuses it's power to take advantage of buy side participants who have "Main streets" best interest at heart. In fact, HFT firms are the small guys bringing efficiency at the cost of the powerful entrenched buy side middle men.
