Reddit also got hammered pretty hard by legitimate traffic last night. There were many thousands of people in the Boston live update threads hitting refresh over and over all night. The admins actually locked the first update page because they said that so much traffic on an article with so many comments would crash the site.

If there's a malicious DDOS attack then this surge in legitimate traffic likely compounded the problem.

The update threads: [1] http://www.reddit.com/r/news/comments/1co395/live_updates_of... [2] http://www.reddit.com/r/news/comments/1cnwms/mods_removed_th...

Where the updates moved when reddit went down: [3] https://twitter.com/JpDeathBlade