http://yw7nc56v4nsudvwewhmhhwltxpncedfuc43qbubj4nmwhdhwtiu4o6yd.onion/t/why-we-abandoned-matrix-the-dark-truth-about-user-security-and-safety/224
Reactions to end-to-end-encrypted (e2ee) messages, because reactions aren’t encrypted. Room related metadata (even for e2ee rooms), room participants and their avatars/nicks, the room topic, power levels, number of messages people sent and when, etc. URL previews of shared links (if enabled on a per room setting) Active attacks A malicious admin can perform active attacks against their users and the rooms they participate in if they want.