Updated

A former software engineer from suburban Chicago who pleaded guilty in 2012 to stealing source code from a U.S. electronic trading company for a project in China isn't going to prison.

Chunlai Yang of Libertyville was sentenced Tuesday to four years of probation for stealing software that underpinned the CME Group's Globex trading platform.

Prosecutors said the 50-year-old Yang downloaded more than 10,000 source code files used at the Chicago Board of Trade and the Chicago Mercantile Exchange.

Prosecutors wanted a six-year prison term for Yang. They said not punishing Yang would encourage more corporate espionage.

However, U.S. District Judge John Darrah said the case was a classic example of "when good people do bad things." He cited Yang's charity work for the "exemplary life" he'd led until the theft.