Open source hardware has been around since the early days of electrical & electronic modules and subsystems. Arguably, my first office mate, Evan Colton, designed an early piece of open source hardware, the first sucessive approximation analog to digital converter. Whether or not we intend it, designs get copied all the time. My first hardware design, a 100MHZ video digital to analog converter with unprecidented low glitch energy. Within 6 months, a west coast company cloned the design, which I considered to be the highest flattery a designer could receive. Ironically, my company sued them for copyright on the data sheet (which they were careless about copying), and won. Today, the biggest difference in open-source hardware is in the area of programmably alterable circuitry, and the accompanying open-source code for popular configurations.
True! I've heard many people refer to open source hardware as a return to the free data roots of innovation. We used to share our tools freely! However, we also used to be paid primarily for skills, mass manufacturing changed that.