Would definitely make it so people need to select to be exit nodes, after being given a warning about what it means to be an exit node. I think it is primarily the lack of clearnet access. Let's face it, most hidden services are boring. I have never looked at the I2P eepsites but my guess is that they are about as boring as Tor hidden services tend to be, if not more so. I guess there are some I2P torrent sites but I have heard torrenting through I2P is still pretty slow. In the case of Tor you may have a larger user group to blend into, but the thing is that this will not protect you if an attacker is positioned to do a timing attack against you. If you use Freenet there might be a 90% chance that you are trading CP, but actually proving that somebody is trading CP on Freenet is arguably a lot harder than proving somebody is trading CP on Tor. In the case of Tor, if the attacker owns your entry guard and can observe your traffic arrive at the destination, you are screwed. In the case of Freenet the attacker can be your 'entry node' and indeed the entry node always can see the content they pass to you, but they can still not easily prove that you requested the content. Just look at the recent HSDIR attack. An attacker is capable of being all HSDIR servers for a hidden service. That means they have the ability to constantly be positioned for 1/2 of a timing attack against any hidden service, and the clients accessing any hidden service. If they own 33.3333% of the bandwidth of the (I think?) 900 or so entry guards, they can deanonymize close to 100% of people who access the targeted hidden service within 60 days. That is the level of an attacker that can deanonymize almost all users of a targeted hidden service: if they can do the HSDIR attack and if they contribute 33.3333% of the entry guard bandwidth for 60 days. Even if they contribute less bandwidth and wait for 30 days, they are still going to be able to do some serious damage. Even if they own only a fraction of the entry guard bandwidth, they will be able to do serious damage over many months. Layered entry guards could be good for hidden services, but as it stands the attacker doesn't need to own the hidden services entry guards to do an edge timing attack against clients connecting to the hidden service. The attacker only needs to own the HSDIR nodes of the hidden service, or the introduction nodes of the hidden service. Permanent entry guards would also be a good idea, but I doubt the Tor developers ever implement that because it would lead to a lack of resource balancing. I have used a transproxy to do Tor -> I2P once before actually. Actually I used Tor to connect to Freenet myself in the past, no transproxy involved . Transproxies are neat but I don't think that they will offer the anonymity required unfortunately. Tor to Freenet is probably pretty good though.