Why programs must not limit the freedom to run them
Specifically, it means the software comes with four essential freedoms that software users deserve. At the head of the list is freedom zero, the freedom to run the program as you wish, in order to do what you wish.
Some developers propose to place usage restrictions in software licenses to ban using the program for certain purposes, but that would be a disastrous path.
Richard Stallman's latest article explains why freedom zero must not be limited.