"Today we have what we didn't have 20 years ago - powerful enemies," Stallman said. Large companies have the means and motivation to lobby Congress and devise laws to prohibit the free distribution of software, he said.

"Without [the freedom to run a program], you are the prisoner of the software you're using," Stallman said. "Free software also means no one has power over anyone else. In contrast, proprietary software works under the dictatorship of the developer."