FYI misskey does not implement the masto api. some software like pleroma/akkoma, gotosocial and yes, a few misskey forks do (in various states of brokenness, with iceshrimp being the most compliant one) but misskey itself does not.
the little eye in the top right corner can be used to toggle all of them in one go. this is such a massive qol improvement it's genuinely baffling how mastodon and the 2 misskey forks I implemented it in are the only fedi software that have that button
I'm not entirely sure if such an instance exists, but just letting you know that in case you can't find any, a reasonable compromise would be to join an instance that's enforcing authorized fetch (and is blocking threads)
this will make it harder for facebook to read your data through federation alone (i.e. even if a post of yours get boosted by someone with followers from threads, it won't "leak" there)
there are ways to bypass this of course but if facebook is found to do something of that sort they would out themselves as actively malicious which would definitely get a reaction even from the "wait and see" crew
it works wonderfully if you want a small tight knit community, but not for something that aims to replace something on the scale of twitter (without something extra like federation, which is still not ready in bsky/atproto)
I got this from the curatedtumblr discord the shank key UI doesn't even let me download videos on mobile
(also remember what I said about custom emojis on Lemmy? yea it looks gigantic from here, might want to avoid using them until apps find a way to differentiate them from regular inline MD images)
you can disable the webpage and unauthorized API if you so choose. mastodon and pleroma/akkoma provide these settings. gotosocial hides all posts with an unlisted visibility from public pages.
authorized fetch only provides protection for activitypub, it's just a single component of a layered stack of protection you can enable depending on your exact threat model.
the privacy threat model of Lemmy is significantly different from a microblog, which is the current target of threads.
i have attempted to build my own federated stuff (none of them actually federated "in real life" though) so i did read the specs but quite a lot of these are from my memory and if there's anything i know is that my memory fuckin sucks lol
mastodon.social sends a single federation activity to www.threads.net's sharedInbox. threads's internal systems handle all the visibility and routing to followed users and whatnot. the same thing happens in the opposite direction for threads->mastodon (or whoever).
now in theory this is an optional part of the specification and you can in fact send one activity per person if you really want to, but considering how widespread it is (and how relatively easy it is to implement) you'd have to be intentionally and explicitly malicious to not use a sharedInbox if the remote server indicates it supports it.
sure let me just walk to a better country
hey wait why are there people with guns around me