To view our videos, you need to
enable JavaScript. Learn how.
install Adobe Flash 9 or above. Install now.

Then come back here and refresh the page.

Twitter officials say the outage began at about 9 a.m., and that they are continuing to fend off a so-called "denial-of-service attack," which happens when hackers clog traffic by sending scores of computers to a single site simultaneously.

Facebook also says it is looking into possible problems after the social networking website seemed to be experiencing slowdowns throughout the morning.