Based on data from https://fedipact.veganism.social/ it seems that the majority of instances blocks threads.net. I'm sure there's Lemmy instances with either approach that have slipped through the cracks as the list is a work in progress.
The percentage of users doesn't correlate to instances as the biggest instance on the Lemmyverse has roughly 3x the users of the second largest, a NSFW instance, 4x the users of the biggest "niché" instance and 5x the users of what I see as the second largest general purpose instance.
I hope not. I know this is controversial but there’s literally no benefit from defederating. People can simply block threads at a personal level if they want.
Even if you do, everything on Lemmy is public so you gain no privacy advantage by blocking it. The only thing you might prevent is a reduction in content quality, but again, if that bothers you just block the instance yourself.
This is a classic kneejerk reaction where people are trying to prevent a hypothetical harm before it has even proven to be a problem.
There might be no benefit to you but the people who would be the direct targets of every hate group like LibsOfTikTok currently active on Threads probably feel a bit differently.
This is in no way a knee-jerk reaction to a hypothetical alarm. Meta have directly contributed to a genocide and allow hate groups to grow unchecked on Threads. It blows my mind that the fediverse - itself built as a series of alternatives to shitty companies doing shitty things - thinks the harm Meta will do is hypothetical and unproven.
The benefits to not federating are many, but the best one, in my opinion, is not exposing current fediverse users who will be targeted to those who will target them.
And that’s why you can personally block it like any other instance in your settings. It’s no different than blocking a lemmy instance that also harbors those exact same kind of people.
At the moment, Threads runs from one domain. Do you seriously think it's going to stay that way? They also have 100 million users, compared to less than 2 million across the entire fediverse. Once Threads gets serious about federation - maybe a year or two from now - what you're suggesting is going to be like constant whack-a-mole. That's in no way a fun prospect.
And even if they stick with one domain (which they won't) - the hate groups on Threads will still be producing content that other fediverse users will be talking about/linking to/quoting etc. The fediverse is very quickly going to become a miserable place to be for those who thought they had found a place where they could be free of all that harassment.
Mastodon, which has far more users than lemmy, implements "authorized fetch", which can actually affect whether Meta can just crawl it.
I know we're on lemmy, but it's not the case that anything on ActivityPub is necessarily fully public, or that instance-level blocking is identical to user blocking.
You’ve only made the case to implement authorized fetch on lemmy. Mastodon did it, Pixelfed did it. No reason why lemmy cannot do it.
edit:
To be clear, I don’t give a rat’s ass what lemmy instance admins do in this matter. Threads interaction is more compatible with mastodon and pixelfed anyway. I just think the chicken little act is ridiculous when bad actors of concern are definitely already here. You’re not stopping anything from coming in. This place isn’t untainted like freshly fallen snow. It’s a pool that gets peed in on a regular basis.
By federating your instance to Threads, you are providing more content to Meta for them to place ads next to, supporting a network that allows abuse orgs like Libs of TikTok with limited moderation.
Consider this scenario: LoT sees a post you made on Lemmy. They select you as a random target of hate, as they did hundreds of people at the beginning of this year.
Their followers start going after you, but you don't know it because you block them. It turns to real life harassment.
Honestly, even if I agree in principle, the fediverse has exhausted any sympathy from me given that there's consistent toxicity towards people who don't "get it", people who aren't open-source tech nerds or fediverse evangelists. There's this constant smugness that the fediverse and its community is better than everything else and it has no problems or the problems that do exist is how the fediverse should work. No, not everyone is like that, but the ones that are make the fediverse experience that much more painful and I'd rather just use Bluesky, even though it's janky and much more limited in features.
Not even talking about Threads, either. I think this issue is quite prevalent on Lemmy but I remember Technology Connections having this issue on the Mastodon side to the point where he got angry too.