This would be a great feature - it's one of the best things about Mastodon. You can't filter out all the idiots one-by-one, but then you see someone two people posting some sus anime, or fubar politics, and you can block thousands of idiots with three clicks. It's very satisfying.

Given Lemmy's conversational layout, I wonder if there aren't hidden difficulties. Like if there's a conversation which goes like this:

.
├── person_0
├── idiot_0
│   ├── person_1
│   ├── person_2
│   ├── idiot_1
├── person_3
│   ├── idiot_1

...then which comments should you see? If you block all the idiots, but not replies, then you can't understand the conversation.

I suspect blocking idiots and all replies would work, but I'm not sure.

site admin can do it on the Blocked instances list.

admins can do that. def needs more levels https://github.com/LemmyNet/lemmy/issues?q=is%3Aissue+is%3Aopen+community+filter

make yourself heard.

I’m curious why you would need to block an entire instance when you can simply ignore it? Nothing from another instance would show up in yours unless you’re following it.