And now replace the "Freenet" in your sentence with "Internet". The sentence is still valid. But would this be a reason to shutdown the Internet or to not run any Internet backbone routers?
Tor gives the impression of being a sea of kidporn with little islands of interesting stuff, especially when you factor in the cognitive fact that human beings give greater weight to negative stimuli.
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The real problem here is child abuse, and people should focus on this. Sometimes I think that actually our society don't really care about the children: it's more like they just don't wanna know and that's why the common answer from the govt is "filter the Internet". IMO the best we can do is think how we can find the child being molested on certain pic, not trying to figure out some magical way to stop distribution, because if we keep trying this we're just wasting the(ir) time...