The Tor network is comprised of thousands of volunteer-run relays around the world, and millions of people rely on it for privacy and freedom online everyday. To monitor the Tor network's performance, detect attacks on it, and better distribute load across the network, we employ what we call Tor bandwidth scanners.
The latest Tor alpha release included a new feature to address traffic congestion in the Tor network. The new algorithm —Kernel Informed Socket Transport (KIST)— prevents connections between Tor relays from becoming overwhelmed by changing how traffic is distributed throughout the Tor network.
Around midnight on August 4th we were notified by a few people that a large number of hidden service addresses have disappeared from the Tor Network.