In Donna Wentworth's excellent Copyfight blog, I had read that Prof. Felten has started a blog of his own, called Freedom To Tinker. I looked at the site, found it interesting, and sent a brief recommendation to a discussion list to which I've been subscribed since (at least) 1996. Felten's work is highly on-topic on that list, and has been discussed there in the past.

One subscriber responded that I shouldn't have recommended bookmarking the site - mirroring it was more appropriate, he said. The blog had gone away.

First, I thought it was a "minor" technical glitch which would be fixed soon. But this afternoon, I learned that the glitch wasn't actually technical: Somehow, my recommendation had made it to SpamCop. SpamCop sent a complaint to the ISP hosting the site, apparently alleging that the site was being advertised through spam. The ISP took the blog off the net, and reported the issue as "resolved" to SpamCop. The individual who had sent the original complaint to SpamCop has confirmed that the report was in error, but had problems to reach someone at SpamCop in order to revoke the report. The web site is still down.

Of course, this is absurd.

But it illustrates quite well the risks connected to simple-minded notice-and-takedown mechanisms - in particular when these mechanisms are coupled with error-prone methods for detecting "criminal" behaviour. ISPs may have a strong incentive to perform the online equivalent of a preliminary execution of their own customers before even asking what's up, or checking the facts. On a certain scale, fact-checking may even become impossible for ISPs' abuse departments, and ISPs have to make up their minds whether they fail in favor of their customers' interests, or in favor of complainants who may be speaking up on behalf some imaginary common good of the Internet - or on behalf of real or imaginary "intellectual property" holders.

Update: Almost 24 hours later, Felten's page is back online, with some remarks on how Spamcop operates, and why his ISP shut down the site.