I’m confused about what kind of data you want to protect. If you mean your posts and comments, they are already publicly availible on the Internet. Meta doesn’t need to make a activitypub app that gets federated with Lemmy (or kbin) to aggregate and sell this data.
Is there an other kind of data that is visible only to server administrators?
Can’t they aggregate and sell your Lemmy activity data without federating with your sever? It’s all in the public Internet.
I guess it won’t be that useful if they have no way of tracking you. But, I don’t think federation makes it easier to track users. Do sever admins get ip addresses of every user on a server they federate with?
Yes, they also haven’t implemented extension support yet.