Why programs must not limit the freedom to run them
Free software means software controlled by its users, rather than the reverse. 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. This article explains why freedom zero must not be limited. Conditions to limit the use of a program would achieve little of their aims, but could wreck the free software community.
First of all, let's be clear what freedom zero means. It means that the distribution of the software does not restrict how you use it. This doesn't make you exempt from laws. For instance, fraud is a crime in the US—a law which I think is right and proper. Whatever the free software license says, using a free program to carry out your fraud won't shield you from prosecution.
A license condition against fraud would be superfluous in a country where fraud is a crime. But why not a condition against using it for torture, a practice that states frequently condone when carried out by the “security forces”?
A condition against torture would not work, because enforcement of any free software license is done through the state. A state that wants to carry out torture will ignore the license. When victims of US torture try suing the US government, courts dismiss the cases on the grounds that their treatment is a national security secret. If a software developer tried to sue the US government for using a program for torture against the conditions of its license, that suit would be dismissed too. In general, states are clever at making legal excuses for whatever terrible things they want to do. Businesses with powerful lobbies can do it too.
What if the condition were against some specialized private activity? For instance, PETA proposed a license that would forbid use of the software to cause pain to animals with a spinal column. Or there might be a condition against using a certain program to make or publish drawings of Mohammad. Or against its use in experiments with embryonic stem cells. Or against using it to make unauthorized copies of musical recordings.
It is not clear these would be enforcible. Free software licenses are based on copyright law, and trying to impose usage conditions that way is stretching what copyright law permits, stretching it in a dangerous way. Would you like books to carry license conditions about how you can use the information in them?
What if such conditions are legally enforcible—would that be good?
The fact is, people have very different ethical ideas about the activities that might be done using software. I happen to think those four unusual activities are legitimate and should not be forbidden. In particular I support the use of software for medical experiments on animals, and for processing meat. I defend the human rights of animal right activists but I don't agree with them; I would not want PETA to get its way in restricting the use of software.
Since I am not a pacifist, I would also disagree with a “no military use” provision. I condemn wars of aggression but I don't condemn fighting back. In fact, I have supported efforts to convince various armies to switch to free software, since they can check it for back doors and surveillance features that could imperil national security.
Since I am not against business in general, I would oppose a restriction against commercial use. A system that we could use only for recreation, hobbies and school is off limits to much of what we do with computers.
I've stated some of my views about other political issues, about activities that are or aren't unjust. Your views might differ, and that's precisely the point. If we accepted programs with usage restrictions as part of a free operating system such as GNU, people would come up with lots of different usage restrictions. There would be programs banned for use in meat processing, programs banned only for pigs, programs banned only for cows, and programs limited to kosher foods. Someone who hates spinach might write a program allowing use for processing any vegetable except spinach, while a Popeye fan might allow use only for spinach. There would be music programs allowed only for rap music, and others allowed only for classical music.
The result would be a system that you could not count on for any purpose. For each task you wish to do, you'd have to check lots of licenses to see which parts of your system are off limits for that task.
How would users respond to that? I think most of them would use proprietary systems. Allowing any usage restrictions whatsoever in free software would mainly push users towards nonfree software. Trying to stop users from doing something through usage restrictions in free software is as ineffective as pushing on an object through a long, soft, straight piece of spaghetti.
It is worse than ineffective; it is wrong too, because software developers should not exercise such power over what users do. Imagine selling pens with conditions about what you can write with them; that would be noisome, and we should not stand for it. Likewise for general software. If you make something that is generally useful, like a pen, people will use it to write all sorts of things, even horrible things such as orders to torture a dissident; but you must not have the power to control people's activities through their pens. It is the same for a text editor, compiler or kernel.
You do have an opportunity to determine what your software can be used for: when you decide what functionality to implement. You can write programs that lend themselves mainly to uses you think are positive, and you have no obligation to write any features that might lend themselves to activities you disapprove of.
The conclusion is clear: a program must not restrict what jobs its users do with it. Freedom zero must be complete. We need to stop torture, but we can't do it through software licenses. The proper job of software licenses is to establish and protect users' freedom.