New York Attorney General Eric Schneiderman sent subpoenas to at least six high-frequency trading firms this week, according to a report from The Wall Street Journal. Those firms can thank Michael Lewis, who called the U.S. stock market "rigged" in his book Flash Boys, which came out in March. 

The Journal's Scott Patterson reports, "The attorney general is seeking details about whether the trading firms have secret arrangements with stock exchanges or other trading venues, such as dark pools, that give them the ability to trade ahead of other investors." This is the kind of behavior that Lewis explains and derides in Flash Boys, which has been making waves on Wall Street and across the country. While traders insist high-frequency trading is old news, Lewis says that doesn't mean it's not wrong. High-frequency trading, or HFT, relies on ultra-fast computers and complex algorithms to make trades quicker than the next firm. Humans don't actually make the trades, the computers do, in a matter of milliseconds. 

Schneiderman (whom Fox political analyst Donald Trump has called the "dumbest attorney general" in the U.S.) has made it his mission to crack down on illegal practices on Wall Street. Whether or not HFT breaks the law remains to be seen — with the subpoenas, Schneiderman is looking for evidence like "emails and other communications related to trading strategies and whether those strategies are enabled by special deals other trading outfits aren't privy to." He calls practices that allow high-frequency traders to act first on market-moving info "Insider Trading 2.0." 

According to Patterson, Chicago's Jump Trading LLC and Chopper Trading LLC, as well as New York's Tower Research Capital LLC, were among the subpoenaed firms. These firms have not commented on the investigation, though plenty of Wall Street-ers have complained about Lewis in the press. Politico's Mike Allen, at least, is not 100 percent convinced Scheiderman's actions are a direct result of Flash Boys' publication. "MICHAEL LEWIS GETS RESULTS (or at least lucky)," Allen writes in Playbook on Thursday morning.