Hellthread
Mastodon/Fediverse phenomenon: a thread that grows uncontrollably as more people are @-mentioned and everyone gets a notification for every new reply. Result: notification hell for all involved.
Cause: Mastodon keeps all @-mentions when you reply → a thread with 20 participants means every new reply pings 20 people. A classic beginner mistake is not trimming mentions. Remedies: remove unnecessary mentions, "mute conversation", or use a client that filters. Bluesky avoids the problem (notifications per-thread, not per-mention). Culturally: "the hellthread" sometimes refers to a specific infamous never-ending thread on an instance. A symptom of the Fediverse inheriting Twitter's thread model without Twitter's notification dampening.