When a group of fans of the Dune books received a copyright threat from the estate of Frank Herbert, they took the path of least resistance: they renamed and altered their re-creation of the novel's setting – a loving tribute created inside the virtual world of Second Life – so that it was no longer so recognisable as an homage to Herbert's classic science fiction novels.

The normal thing to do here is to rail at the stupidity of the Herbert estate in attacking these fans. After all, they weren't taking money out of the pockets of the estate, the chance of trademark dilution in this case is infinitesimal, the creators were celebrating and spreading their love for the series, they are assuredly all major fans and customers for the products the estate is trying to market, their little Second Life re-creation was obscure and unimportant to all but its users, and the estate's legal resources could surely be better used in finding new ways to make money than in finding new ways to alienate its best customers.

But that's not what this column is about. What I want to ask is, how did we end up with a copyright law that only protects critics, while leaving fans out in the cold?

Some background: copyright's regulatory contours allow for many kinds of use without permission from the copyright holder. For example, if you're writing a critical review of a book, copyright allows you to include quotations from the book for the purpose of criticism. Giving authors the right to choose which critics are allowed to make their points with quotes from the original work is obvious bad policy. It's a thick-skinned author indeed who'd arm his most devastating critics with the whips they need to score him. The courts have historically afforded similar latitude to parodists, on much the same basis: if you're engaged in the parodical mockery of a work, it's a little much to expect that the work's author will give her blessing to your efforts.

The upshot of this is that you're on much more solid ground if you want to quote or otherwise reference a work for the purposes of rubbishing it than if you are doing so to celebrate it. This is one of the most perverse elements of copyright law: the reality that loving something doesn't confer any right to make it a part of your creative life.

The damage here is twofold: first, this privileges creativity that knocks things down over things that build things up. The privilege is real: in the 21st century, we all rely on many intermediaries for the publication of our works, whether it's YouTube, a university web server, or a traditional publisher or film company. When faced with legal threats arising from our work, these entities know that they've got a much stronger case if the work in question is critical than if it is celebratory. In the digital era, our creations have a much better chance of surviving the internet's normal background radiation of legal threats if you leave the adulation out and focus on the criticism. This is a selective force in the internet's media ecology: if you want to start a company that lets users remix TV shows, you'll find it easier to raise capital if the focus is on taking the piss rather than glorifying the programmes.

Second, this perverse system acts as a censor of genuine upwellings of creativity that are worthy in their own right, merely because they are inspired by another work. It's in the nature of beloved works that they become ingrained in our thinking, become part of our creative shorthand, and become part of our visual vocabulary. It's no surprise, then, that audiences are moved to animate the characters that have taken up residence in their heads after reading our books and seeing our movies. The celebrated American science-fiction writer Steven Brust produced a fantastic, full-length novel, My Own Kind of Freedom, inspired by the television show Firefly. Brust didn't – and probably can't – receive any money for this work, but he wrote it anyway, because, he says, "I couldn't help myself".

Brust circulated his book for free and was lucky enough that Joss Whedon, Firefly's creator, didn't see fit to bring legal action against him.

But if he had been sued, Brust would have been on much stronger grounds if his novel had been a savage parody that undermined everything Whedon had made in Firefly. The fact that Brust wrote his book because he loved Whedon's work would have been a mark against him in court.

This isn't a plea for unlimited licence to commercially exploit the creations of others. It's fitting that commercial interests who plan on making new works from yours seek your permission under the appropriate circumstances. Nor is this a plea to eliminate the vital aid to free expression that we find in copyright exceptions that protect criticism.

Rather, it's a vision of copyright that says that fannish celebration – the noncommercial, cultural realm of expression and creativity that has always accompanied commercial art, but only lately attained easy visibility thanks to the internet – should get protection, too. That once an artist has put their works in our head, made them part of our lives, we should be able to live those lives.