Going to talk about free software - a point that's often lost. Some people prefer to talk about "open source software", avoiding the ethical issues.

The Four Essential Freedoms

• Freedom 0: Freedom to run the program as you wish
• 1: Study and change the source code
• 2: Freedom to distribute copies (help your neighbor)
• 3: Freedom to distribute modified copies (help the community)

Non-free software keeps the users divided and helpless. Divided because they can't all use it, helpless because they can't change it.

Why are these four freedoms essential?

• Freedom 2 is essential to leading a moral life. [Why? I guess because you should help people if they ask. -ed] If your friend asks for a copy, and you aren't supposed to give it to him, you should give it to him anyway. If you have to do wrong to someone, do it to the developer who deserves it, because they asked you to accept an agreement that violates Freedom 2. But not accepting that agreement in the first place is even better than violating it (ie use free software.)
• Freedom 0: you must reject software that restricts your ability to use it. But this depends on Freedom 1, because if you can't study the source you won't know how it might be restricting your usage or doing other evil things (eg spying on you.) "There are lots of proprietary software developers and they're all evil."
• You can imagine what he thinks about DRM.
• You can't trust software that doesn't come with source - Microsoft built backdoors for the US government into Windows. And even if it's not intentionally doing evil, it'll have bugs.
• The result of these four freedoms is democracy.

Now he's talking about how the OS popularly known as Linux is actually GNU software plus a kernel. And complaining about how Linus isn't a free software advocate and talks about "open source", thus not supporting social solidarity. He actually says "GNU/Linux", as in "GNU slash Linux".