My latest Guardian column is up: "Online censorship hurts us all," about the ways that copyright protection laws that make it easier to censor artists are worse for creativity than any amount of unauthorized copying could ever be.
Viacom and others want hosting companies and online service providers to preemptively evaluate all the material that their users put online, holding it to ensure that it doesn't infringe copyright before they release it.
This notion is impractical in the extreme, for at least two reasons. First, an exhaustive list of copyrighted works would be unimaginably huge, as every single creative work is copyrighted from the instant that it is created and "fixed in a tangible medium".
Second, even if such a list did exist, it would be trivial to defeat, simply by introducing small changes to the infringing copies, as spammers do with the text of their messages in order to evade spam filters.
In fact, the spam wars have some important lessons to teach us here. Like copyrighted works, spams are infinitely varied and more are being created every second. Any company that could identify spam messages — including permutations and variations on existing spams — could write its own ticket to untold billions.