"Back of the Book" can be achieved by increasing your order quantity. It isn't illegal. To this day the CME's api states that if you increase your quantity you "lose priority" a.k.a. you move to the back of the book. Not illegal, and is actually very fair. If one tried to add 20 friends to your spot in line while waiting for concert tickets you would be asked to move to the back of the queue. Reference [CME Specs for cancel replace quantity increase.](
https://www.cmegroup.com/confluence/display/EPICSANDBOX/Orde...)
Trader A is identified. He (Sarao) made millions off his trading and spoofing. Jitesh and Edge Financial were only paid $24,000 for their programming work.
According to the motion to dismiss (which the judge ruled was arguments for trial):
> The indictment against Jitesh contains no allegations
> that Sarao ever told Jitesh that he planned to spoof,
> move the market, or engage in any other illegal activity,
> which is consistent with Sarao’s FBI interview reports
> in which he told the government that he did not tell
> Jitesh what he planned to do. This is also consistent
> with Sarao’s indictment, which recounts Sarao’s
> conversations about his intent to spoof with the other
> three programmers over five pages of the indictment,
> but only contains one reference to Jitesh: “In
> approximately late 2011, SARAO began working with
> [Jitesh], to further develop the automated trading
> programs and functions he had been working to design
> and implement since early 2009.”