An overview of ISP Voluntary / Mandatory Filtering

Irene Graham of Electronic Frontiers Australia has compiled an invaluable overview of ISP level filtering systems as part of the EFA campaign against mandatory filtering in Australia. What's most striking about her survey is that unlike much previous work which focused on countries such as China or Saudi Arabia, she looks at the systems put in place in various democracies (including Canada, the United Kingdom and Finland) but still finds the same problems - a lack of democratic legitimacy, opaque systems, overblocking, and indications of function creep.