In light of BT being ordered by the High Court to block links aggregation service Newzbin on copyright grounds, I'm reminded of a discussion taking place several years ago.
When the Internet Watch Foundation (IWF) was established and some UK ISPs started blocking sites hosting images of child abuse very few people were willing to fight this move in public.
The establishment of the IWF and installation of systems to block websites was seen as a dangerous step towards censorship by civil rights campaigners at the time, but it was also a highly-focussed and tightly-controlled censorship mechanism in which the state played no role.
So the majority of civil rights campaigners accepted the system as part of the imperfect compromise in every democracy.
But one interesting discussion I was party to many years ago centred around whether an ISP's legal rights would shift if they installed a blocking system commonly referred to by its trade name Cleenfeed.
Under Article 12 of the European Directive on E-Commerce ISPs have a defence against most illegal activity taking place on their network known as "mere conduit" defence.
Essentially, any service provider can only be expected to police content on their networks if they are both (a) reasonably made aware of the infringing behaviour; and (b) reasonably in a position to stop the infringing behaviour.
Most ISPs had the mere conduit defence because it was not considered reasonable to ask an ISP to block access to certain websites, whilst providing open access to all others. ISPs were, for want of a better phrase(!), just a pipe - or conduit - to the outside world. ISPs accept data packets, and pass them on according to a set of rules. Nothing more, nothing less.
Many commentators at the time however speculated that the installation of Cleenfeed as part of the IWF blocking scheme shifted the role of the ISP. An ISP running a Cleenfeed-type system may no longer be classed as a "mere conduit" as defined under EU law because it was making a decision whether or not to pass-on each packet which entered the network.
I haven't absorbed the full ruling yet from the Newzbin case, but I'm reminded of this previous discussion and wonder whether, in attempting to do some good in the world, ISPs have lost their legal protection and will now be expected to police all content, not just block images of child abuse.