p.s. If you're sceptical about what is said in this post, try putting yourself into this thought experiment: https://social.chinwag.org/@FediThing/112581263140051643

If you think the thought experiment is unlikely to happen, here's a real life example where exactly this did happen: https://social.chinwag.org/@FediThing/115061048964841034

@FediGarden plus, users might not be aware their posts end up in Meta's databases, and we know Meta is happy to exploit the data they do have in most obnoxious, creepy, and horrible ways, like:
https://www.theguardian.com/technology/2025/sep/20/parents-outraged-meta-uses-photos-schoolgirls-ads-man

Making it a more explicit decision – having to change the instance, or making Threads blocked by default and allowing the people using the instance to unblock it if they'd want to – makes more sense to me.