Bruce Abramson, JD, PhD

Imagine a friend borrows your car for a week. He promises to bring it back clean and full of gas. Reasonable enough, until you discover he racked up 1,500 miles because, while he wasn’t using it, he let his cousin run Uber shifts with it and pocketed a cut of the fares. You didn’t agree to that. You agreed to one driver, one purpose. The cousin had no right to free ride on your investment, devalue your property, or make money off your car without permission. Is it theft? Not quite. But it’s a textbook example of “conversion”—getting hold of something legally to use for a specific purpose, then deploying it in a very different manner. That, in essence, is what Zillow stands accused of doing to CoStar: Co-opting photos that CoStar put into public view, without authorization, to drive its own profits. The alleged free ride could cost Zillow nearly $7 billion.