Now in the early centuries of printing, and still I believe in the 1790s, lots of readers wrote copies by hand because they couldn't afford printed copies. Nobody ever expected copyright law to be something other than an industrial regulation. It wasn't meant to stop people from writing copies, it was meant to regulate the publishers. Because of this it was easy to enforce, uncontroversial, and arguably beneficial for society.
It was easy to enforce, because it only had to be enforced against publishers. And it's easy to find the unauthorized publishers of a book—you go to a bookstore and say “where do these copies come from?”. You don't have to invade everybody's home and everybody's computer to do that.
It was uncontroversial because, as the readers were not restricted, they had nothing to complain about. Theoretically they were restricted from publishing, but not being publishers and not having printing presses, they couldn't do that anyway. In what they actually could do, they were not restricted.
It was arguably beneficial because the general public, according to the concepts of copyright law, traded away a theoretical right they were not in a position to exercise. In exchange, they got the benefits of more writing.
Now if you trade away something you have no possible use for, and you get something you can use in exchange, it's a positive trade. Whether or not you could have gotten a better deal some other way, that's a different question, but at least it's positive.
So if this were still in the age of the printing press, I don't think I'd be complaining about copyright law. But the age of the printing press is gradually giving way to the age of the computer networks—another advance in copying technology that makes copying more efficient, and once again not uniformly so.
Here's what we had in the age of the printing press: mass production very efficient, one at a time copying still just as slow as the ancient world. Digital technology gets us here: they've both benefited, but one-off copying has benefited the most.
We get to a situation much more like the ancient world, where one at a time copying is not so much worse [i.e., harder] than mass production copying. It's a little bit less efficient, a little bit less good, but it's perfectly cheap enough that hundreds of millions of people do it. Consider how many people write CDs once in a while, even in poor countries. You may not have a CD-writer yourself, so you go to a store where you can do it.
This means that copyright no longer fits in with the technology as it used to. Even if the words of copyright law had not changed, they wouldn't have the same effect. Instead of an industrial regulation on publishers controlled by authors, with the benefits set up to go to the public, it is now a restriction on the general public, controlled mainly by the publishers, in the name of the authors.
In other words, it's tyranny. It's intolerable and we can't allow it to continue this way.
As a result of this change, [copyright] is no longer easy to enforce, no longer uncontroversial, and no longer beneficial.
It's no longer easy to enforce because now the publishers want to enforce it against each and every person, and to do this requires cruel measures, draconian punishments, invasions of privacy, abolition of our basic ideas of justice. There's almost no limit to how far they will propose to go to prosecute the War on Sharing.
It's no longer uncontroversial. There are political parties in several countries whose basic platform is “freedom to share”.
It's no longer beneficial because the freedoms that we conceptually traded away (because we couldn't exercise them), we now can exercise. They're tremendously useful, and we want to exercise them.