What is a Denial of Service or Distributed Denial of Service Attack?

The US-CERT (United States - Computer Emergency Readiness Team) has published a document on Denial of Service and Distributed Denial of Service (often abbrieviated DoS or DDoS) attacks which can be found at the following URL: http://www.us-cert.gov/cas/tips/ST04-015.html

The document is fairly easy reading and highly recommended for everyone from the novice to more technical computer users.  It is important to be aware of these types of attacks and understand that it is not just large corporations that get attacked; it is also possible for a malicious user to go after an individual as well.  Motivation behind these attacks can range from revenge to attempts for recognition among peers.  Some are more militant and may go against critical government web sites, others could be an attempt to go after someone because of post they put in a forum, and some criminals may be bold enough to request a ransom to stop the attacks against a high profile company.

Read the article and the next time you can't access a web site you may begin to wonder if the site, or even you could be the recipient of a Denial of Service attack.