For our instance we've answered that here:

Reddit might be forced to hand out IPs of users frequenting piracy subreddits: how does programming.dev compare?

edit: just wanted to share a great observation that was made by UlrikHD in our admin channel:

"So if a company wanted to demand the ip of every member on a piracy community, they would have to contact every instance federated with that community then
good to know"