Z:gnu-www-ja-free-digital-society--6cd169-However, it's not obligatory t/en

However, it's not obligatory to do any of these things. The point is you're free to do them if you wish, when you wish. But you never have to do them. You don't have to do any of them. You don't have to run the program. You don't have to study or change the source code. You don't have to make any copies. You don't have to distribute your modified versions. The point is you should be free to do those things if you wish.