Twitter down, Facebook slowness: What are you seeing? - Digits - WSJ

Facebook, Twitter and LiveJournal all reported denial-of-service attacks Thursday that resulted in service outages, slowness and other problems for the popular Web sites.

Twitter.com displayed an error message — not even its iconic Fail Whale appeared — when accessed. The microblogging service posted a brief message on its status blog around 10 a.m. EST, saying, “We are determining the cause and will provide an update shortly...”