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."
... DVD is encrypted so that it can only be decoded and viewed using an encryption key, which the DVD Consortium kept secret. In order to gain access to the key, a DVD player ...