Let’s say you want to get into the entertainment business. You’re young. You’re willing to do grunt work. You want to learn. You get hired as an intern - maybe you’re paid, maybe you work for free - but you end up doing the work of a regular employee. What does your boss owe you? That’s the question at the heart of a class action lawsuit filed by a former intern against CBS and David Letterman’s production company. It’s the latest in a wave of intern lawsuits against the entertainment industry.