Somewhere around 17:20-17:30 UTC, Cogent readvertised routing to our primary IP address block in Tampa, blocking access to the site for most people.
Partway through the period, wikis were placed into read-only lock so the few people who could access it (mostly from AOL ;) were unable to edit without review from the public.
The route was temporarily restored around 19:55, and read-write was restored to the wikis at 19:59.
The old IP range will no longer be available to us as of Monday.
PowerMedium has assigned us a new IP space which is under their control (unlike the old IPs which were leased from Cogent under an older contract), and we will be transitioning to them over the weekend.
We have heard several conflicting things about exactly why and how our IP space got dropped; more will be said when we have firmer knowledge.
-- brion vibber (brion @ pobox.com)