Echoing Patrik, I too just got a chance to read Pier's document carefully, and I, too, like it :)
In fact, a moment of congratulations and thanks to Pier for striking out and pulling together something comprehensive! The structure is really good, and the lively debate on this thread indicates that the work here is on the right path.
With that, I have one high-level, two-paragraph comment that I hope adds to the discussion.
I would suggest removing the target audience -- here started as law enforcement and governments -- and dedicating this work more broadly to anyone who's interested in this topic and would like a basic understanding of mechanisms and approaches used by *whoever* to block or prevent access to content. This expands the document a bit, but I think presents a clearer conceptual framework: how to actors that want to block content go about doing it, from asking ISPs to block specific IP addresses, to DDOS attacks, to whatever in between. What are the technical means, good or bad?
In that spirit, while I think you've done an admirable job staying away from ascribing a value to specific acts of content blocking/filtering, I would suggest pruning even further. Page 8 and 9 suggest means of using these techniques for "preventing access to illicit content." I would suggest removing this section -- these same technical means are used both to prevent access to child pornography (the canonical example), and to silence political speech and quiet debate that threatens those in power, &c. Insofar as this is a document focused on the means, not the ends, speculating on "good" vs. "bad" modes of filtering/blocking, even implicitly, leads quickly to our having to justify one or another ethical viewpoints, and I think confuses the clarity of the document.
At this stage, I would suggest thinking of others we might want to bring into the discussion. Are there folks who have experience here and could add more detail? Do we want to expand on specific modes of blocking (DPI/filtering boxes, and their similarities and differences, for example)? In my view its always good to add as much as possible in the beginning, ensuring that everything is covered, then remove and distill during the editing process. (And, as before, I'm more than happy to help with editing.)
Cheers, and thanks again,
Meredith