if you post somewhere on the Fediverse, and some Threads user bumps into it, they can follow you, and that will send all that data to Meta. And it looks to include data well beyond the post the Threads user saw.
exactly
and that is why #hubzilla and #streams have a permission system to avoid that... you can set up rules and decide who can see your posts and what they can to with it...
have a look at this FEDI projects
@jackalope
Waht do you mean by that?