We say that running free software on your computer means that its operation is under your control. Implicitly this presupposes that your computer will do what your programs tell it to do, and no more. In other words, that your computer will be loyal to you. In 1990 we took that for granted; nowadays, many computers are designed to be disloyal to their users. It has become necessary to spell out what it means for your computer to be a loyal platform that obeys your decisions, which you express by telling it to run certain programs. Our tentative definition consists of these principles.

via @fsf