In 1974 a 13-year old boy named David Dennis discovered that he could lock up a PLATO terminal by making an external request when no external device was present. This prompted David, a student at University High school in Champaign Illinois, to write a program that could send the request to multiple PLATO terminals at once. He first launched the program on a nearby university computer lab, forcing 31 frustrated students to restart their PLATO terminals. The Denial of Service attack was born.
In early 2000s the attacks used to be spoofed. Over time the botnets evolved and more machines were available to launch larger attacks without the need for spoofing. Now there is a trend to use large data centers with high available bandwidth pipes for launching DDoS attacks which use social tools.
Besides disrupting Internet operations through brute force, since the DDoS attacks against U.S. financial institutions, CIOs understand that well-organized attacks may have intent of disruption of business operations, possibly through destruction of access to business information. DDoS attacks have been used as a shield by malicious actors to break into the financial and e-Commerce accounts of customers without being noticed.