By . For years students flocked to schools run by Corinthian Colleges (COCO), one of the largest for-profit education companies in the U.S. Attracted by late-night TV commercials and Internet ads for vocational certificates and online business degrees, they enrolled on the promise that the extra career training would give them a leg up in the job market. The marketing worked: At its peak, in 2003, the publicly traded company was worth more than $4 billion. About 72,000 students attend Corinthian’s three chains—Everest, Heald, and WyoTech. More...