The U.S. District Court in New York will decide at some point whether Aereo is even legal. Broadcasters say the service, which streams their over-the-air signals to subscribers, infringes on their copyrights — a charge that Aereo denies. But while that fight plays out, the firm hopes to galvanize consumer support in the Big Apple beginning today. It’s offering new customers nearly three months of free service before the $12 a month charge kicks in.  Customers will be able to watch more than 20 local broadcast channels on mobile and other digital devices, as long as they’re in the NYC area. In addition, Aereo offers a DVR-like service that gives users the opportunity to store and watch on demand up to 40 hours of programming. The service will begin serving gadgets that run Apple’s iOS operating system, and promises that support is “coming soon” for Android. “People no longer want to be tethered to their TVs or cable boxes,” CEO Chet Kanojia says. “This truly groundbreaking technology will usher in a new era of choice in the broadcast marketplace, making the consumers the ultimate winners.”