The Volokh Conspiracy is down right now. No, it's not Bad Guys launching a mass Zombie attack - Both Instapundit and Slashdot have simultaneously linked an article. Their poor server is trying to handle eleventy-gazillion requests per second.
See Instalanche, Slashdotted.
The difference between this and a bona fide attack (see Mafiaboy) is that it is a spontaneous action of many web users following a sort of wisdom-of-crowds paradigm, rather than centrally-directed command and control. There's also no malicious intent.
I'm sure that Professor Reynolds could do an interesting article as to whether insufficient scoping of server capacity and bandwidth qualifies as malum in se or not.