First the operators or community members - developers of those two communities can't say that they didn't know because those sites are also indexed in the official and non-official indexes of the sites and content on their network. You don't really have to search and it isn't even closed off to others by asking for registration before you can see anything.
Secondly the defenders of these networks as environments of freedom of expression should take into consideration the following 5 good reasons
* we all defend the freedom of expression, the freedom of normal sexual preferences by adults without the fear of prosecution or whatever harm or discrimination and on the real web we try to stop as much as possible the attacks by governments and corporate interests against that freedom of expression (and some of it use the presence of childporn as an excuse to do other things)
* we are all great believers of democracy and human rights of every individual but also of the rights of children and there is no reason that the rights of children should be less than the rights of humans - even if some bastards think otherwise. If is the same as if you would say that you are for women rights and against slavery but would let propagate market sites where you could buy women from Russia for example. It is not what you say that is important but what you do.
* even if we say that these networks have some illegal activity we must remember that even illegal activities are most of the time not crossing certain borders. If childporn would be normal you would find it quite easily in the redlights districts - which apart from some countries where it is abused by rich westerners is not the case. It means that even if you say that some illegal activity will always be present in these anonymous networks, there is some illegal activity that can't be accepted under any circumstance not because it is illegal but because it so inhuman that even for bandits and crooks it is most of the time unacceptable.
* these networks were build for freedom of expression and to help the dissidents all over the world to publish their beliefs or their research that wouldn't be possible on the normal web. Both of the networks were NOT built to host Childporn and pedostuff, that was not their goal and I believe will never be their goal. At the other side as a dissident I would find myself not really 'at my place' in directories and on hosters that are also hosting 'childporn and pedostuff. Instead of being the first place to look for protection you would be the last place where I would look, because I would feel myself as going through the gutter with people I would like to bang up for life whenever I could.
* it makes your networks very vulnerable and for different reasons. First the police and governments have a good reason with this presence to increase the pressure to break the anonimity of your networks, to confiscate your servers or to block the access to your networks whatever way they can. The other criminal activity is also a important but it doesn't have the same 'shocking value'. If I would publish the pictures of the pedofora on your networks, there would be a public outcry and people would ask police actions NOW. And I understand that you would stand your position for real dissidents and revolutionaries over the world, but for pedophiles ? No, I don't think somebody would stand beside you and say that you were right, that there isn't any and that it is only some discussion and no exchange of pics and so on because that ain't true.
What you can do ?
1. close down the real only Pedofora and exchanges
2. Obligate all pornforums to have registration before viewing things - knowing that you will never clean out the galleries fully all the time
3. ask all the site-owners to close down the pedocategorie in their porngalleries
4. Evaluate the effects of this and adapt your reglementation
5 Do more to attract and mirror the real political stuff and dissidents because for the moment it doesn't impress me much
and what if you don't
than you will die down slowly because you become irrelevant except for criminals and pedo's and weirdo's
and really, was that the ideal for which you have given all these years of efforts as a volunteer
becoming a safe haven for ...... pedophiles who exchange pics and experiences
What if Tor and Freenet don't act ?
* than it is time for Anonymous antipedo to bring down those sites or ddos the servers
* than we should call for a boycot of this wild wild west and start a campaign for a real political safenet where there is no place for such bastards. They should not be protected by our technology.
* build on the normal web encrypted protected hosters and services that are independent of these networks and can give the real political dissidents a real safe encrypted environment for filesharing, messaging, planning and publishing with servers in a country that will never intercept what is happening on and to these servers