Recently, Keynote Systems was asked to comment on a widely publicized attack against a company online. The attack, known as a distributed denial of service(DDoS), was targeted at a network of web servers primarily located in Europe. DDoS attacks against websites have occurred periodically for years. Unlike past incidents, the nature of this particular attack was characterized as severe enough to have caused broad disruption on the Internet. The suggestion made was that users like you and I may have found our email delayed and websites either slow or unavailable.
While many methods exist to understand the impact of web attacks like this, Keynote's web performance, monitoring service and global network provide a unique perspective--the end users' perspective. Keynote business is monitoring websites for their customers so that they have a consistent and accurate source of information about their site's performance. But they also use that same technology to monitor select sites across the Internet and make this data publicly available in the form of an index--actually, 43 indices. And they also use it to provide another free service called The Internet Health Report that shows what's happening across the major U.S. Internet Service Providers in real time.
Keynote periodically test a wide range of websites from their network of hundreds of monitoring agents connected to different ISPs all over the world. These agents pretend to be a site visitor and measure performance during their visit.
One of their indices monitors the U.S. banking sector. The financial services industry has been hit hard of late by DDoS attacks. You can read the Keynote blog post Understanding the Impact of Web Attacks - the User Perspective
Source: Keynote Systems