It's been down for a day, and may be down for a few more. Looks like "Just build your own Internet" isn't a viable option for internet communists, everyone must learn of their peaceful ways by force.
Trying to get to Saidit redirects you to Saidit's Subreddit, in a sad state of affairs.
EDIT:It's come back up since then. Updates in the link.
Six years later, still living rent free...
(archive.is)