@Mastodon Underwhelming.

«It is also not possible for any third party server to insert ad-like posts into your home feed.»

Unless they deliver ads through "normal" posts.

«A server you are not signed up with and logged into cannot get your private data or track you across the web.»

Meaningless sentence as "private data" is not defined; does not seem to speak about "personal data" as in #GDPR sense.

#Instagram, #Facebook can and will track you across the web by linking different identifiers.