With debate raging in the Fedi about Threads' federation, I was having a discussion with another user about the recently implemented instance blocks. They pointed out that, blocking an instance simply hides their content from your feed but doesn't prevent your posts from being sent to them. Firstly, is this correct? Is this how instance blocks are implemented in Lemmy? If not, has this been discussed before? I couldn't find such a discussion in Github issues...
It seems that many people have concerns about Meta's use of their data, and would like to opt out of sharing their content with Threads. Is there any way to do this in Lemmy right now, or any plan to implement such a feature?
There isn't practically any way of blocking your content from being seen on another platform. It's an arms race and you'll always lose. Look at Reddit, they had a whole campaign to kill their API, and most of their quality content is reposted here through bots. If you post something on the internet, there it no way to ensure it doesn't appear on Threads, where you posted the content originally doesn't change that fact.
The reason for not directly federating content to Threads isn't so nobody there can ever see my amazing posts, it's so Meta can't easily profile me. Scraping public posts on a different platform would probably be illegal, at least in the EU, and reposts don't give them a lot of data about me. Federating content, however, would give them most of the same data that Mastodon has on me without even having to ask.
Meta can always profile you from the content you post to the fediverse, and they don't need Threads to do it. In the fediverse, every upvote, every down vote, every comment, every ban, and everything else is a matter of public record that can be easily queried by anyone without logging in to anything.
In the EU companies can't scrape personally identifiable information without consent, even if it's already publicly available. IANAL, and there's probably ways they can sneak around the GDPR, but at least it's not a free for all. It's unclear though how it works for federation. It's definitely not the same legally though.