Former Goldman Sachs Group Inc. programmer Sergey Aleynikov was found guilty in the high-frequency trading code theft case that illustrated the difficulty of using existing law to protect technology central to financial markets. Aleynikov, whose travails helped inspire Michael Lewis’s “Flash Boys,” acknowledged that he breached Goldman Sachs policy by downloading the code to his home computers. While Aleynikov’s attorney, Kevin Marino, argued that taking the code wasn’t illegal even if it violated bank policy, jurors decided it was a crime.