Tens of thousands of malicious routers have been deployed on the peer-to-peer anonymous network, I2P. These malicious routers are not contributing transit, causing severely degraded performance and anonymity for all. It is unknown whether this is the result of state actors, botnets, or researchers at this time.

https://www.reddit.com/r/i2p/comments/1qvalmq/megathread_ongoing_attack_on_i2p_network_causing/

https://github.com/PurpleI2P/i2pd/issues/2312