Wikimedia sites unavailable
All Wikimedia sites – Wikipedia, Wiktionary and so on – are completely unavailable. Wikia (which is run by the same people, but is a for-profit corporation separate from the Wikimedia Foundation) is also screwed, which suggests that there may be a hardware problem/power outage at their server farm (it was all working this morning!).
To top it all off, OpenFacts (a completely separate third-party site that provides an offsite status page for Wikipedia) is returning a database error.