http://lainyubrp2aabmxhepbttfdbl53dct2inqifs42buvpf6w44uiitbeqd.onion/blog/matrix.html
Guy, who operates the server can see: - Chat history of every unencrypted room - Information about the users of their homeserver, like devices, IPs, etc. - Room related metadata, room participants and their avatars/nicks, the room topic, power levels, number of messages people sent and when, etc.