I think you’re fundamentally misunderstanding how data is handled in federated systems. When an account from Threads interacts with your post or you interact with a Threads post, information is exchanged exclusively through Actions sent between the servers- never to or from your or their client and another server. It looks like this:

Client <=API=> Instance <=Action=> Instance <=API=> Client

They don’t get any information that isn’t already available publicly to any random user on your instance- no IP address or anything otherwise. Threads’ mobile app data collection has no bearing on their ability to collect information on you.

Edit: To be clear- there is theoretically a set of protocols in the ActivityPub spec that allows for direct client to server communication (unimaginatively called ActivityPub Client-to-Server), but it hasn’t been adopted by any current Fediverse software implementation that I’m aware of.

What a wild conspiracy theory.

Legally, they can't collect and process any of the data unless you accepted a contract with them. Just by sending an upvote or a comment to their instance, you don't agree to any of this.

And if they choose to ignore the law and just do it anyway, they still can't, because all they have is the data that your instance sends them. They don't have your geo-location, device Id, etc.

I am not getting it. If i am not using their threads client and signed in to a de federating instance, they would not get my IP address right?