The popular micro blogging site, twitter.com, was attacked last Thursday causing it to go offline for several hours.  Another popular social networking site, facebook.com, also slowed down during the attacked.

Twitter suffered a Denial of Service or DOS attack.  DOS is a common type of attack that slows down or totally make a web site go offline.

A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt to make a computer resource unavailable to its intended users. Although the means to carry out, motives for, and targets of a DoS attack may vary, it generally consists of the concerted efforts of a person or people to prevent an Internet site or service from functioning efficiently or at all, temporarily or indefinitely. Perpetrators of DoS attacks typically target sites or services hosted on high-profile web servers such as banks, credit card payment gateways, and even root nameservers.

According to reports, the attack could have been related to the Russia-Georgia political conflict.  Spam e-mails were sent before the attack causing the reader or the recipient to click on a link that goes to pages written by activists on social networking sites such as Twitter and Facebook.

The links in the e-mail were directed to a legitimate website but the number of people who received the email and the number of people clicking the link at almost the same time overwhelmed the sites and caused them to slow down or go offline.

DDoS has been around for quite a while.  I think Twitter needs to make their infrastructure even more stronger because thinking they can be brought down by a DDoS attack simply means they have weak servers and network infrastructure.