1893 - Thomas Edison received two U.S. patents. The first was for a "Cut Out for Incandescent Electric Lamps" and another for a "Stop Device" (No. 491,992-3). Also No. 492,150 for "Process of Coating Conductors for Incandescent Lamps."
... copyright holder. The context is most commonly digital (ie, as in a computer or computerized device), hence the 'digital' in DRM. In contrast to existing legal restrictions ...