Freenet has only symbolic privacy protection for downloaders. Privacy is supposed to come from your node requesting not only blobs it is downloading for itself, but also blobs other nodes have requested from it. Unfortunately, as far as I understand, freenet's routing algorithm is such that these two classes of requests come from blatantly different statistical distributions. The further a requested blob is from a node's address the more likely it is the node is requesting the blob for itself. Another layer of protection is the blocks being encrypted, but if they are publicly published that can be changed with a bit of scraping.

What this means is that by running a single freenet node you can monitor half a hundred others. What's surprising is that it hasn't been done earlier. You don't even have to commit a crime to do it as a civilian.

This could have been avoided if freenet was hoisted on top of tor (not totally trivial because freenet runs over udp) or had an onion routing layer of its own. If the glaring privacy flaw was fixed freenet would have amazing properties which tor lacks, namely very safe and scalable (no dos unless you take down the whole of freenet) static hosting and non-realtime communication in general, and utter censorship resistance. Trying to figure out who has a blob only spreads it around more.

It's a shame the ideas behind tor and freenet haven't come together in a popular project.