But how will they deal with the GDPR?
>I don't expect any major changes are needed for compliance, which is why it's been pretty low priority. it's just a matter of getting a document together that better informs admins.
Mastodon has all the features needed for compliance, and does not collect or store any data that's not for its primary purpose.
edit: I didn't see that this was in the context of GDPR.
Also, doesn't ActivityPub allow closed groups?
It's specific to the use case and what guarantees you have, and not a strict property of a protocol.
personally, i don't care about GDPR since i'm not under EU jurisdiction. even so, none of my servers store logs and i don't require an email address to register.