But there have been computer and network hacks for, well, pretty much as long as we've had computers and networks. The motives behind these intrusions have ranged from curiosity to paranoia (see McKinnon, Gary), through today --when most high-profile hacks are driven by either greed or some form of ideology.
[Related slideshow: Rogues Gallery 2: Ten infamous hacks and hackers]
Here are ten hacking incidents through history that made some of the biggest headlines.
Markus Hess hacks on behalf of the KGB
A German citizen recruited by the KGB to spy for the Soviets in the 1980s, Hess was tasked with breaking into U.S. military computers to obtain classified information.
From the University of Bremen in Germany, Hess used the German Datex-P network via satellite link or transatlantic cable to the Tymnet International Gateway. He was able to eventually attack 400 U.S. military computers, including those at military installations in Germany and Japan, as well as machines at MIT in Cambridge, Massachusetts and the OPTIMIS Database at the Pentagon.
Hess's activity was eventually detected by Clifford Stoll, an astronomer turned systems administrator of the computer center of the Lawrence Berkeley Laboratory (LBL) in California. Hess was found guilty of espionage and sentenced to one to three years in prison.
After Hess's capture, Stoll wrote about the experience in a book titled "The Cuckoo's Egg."
Robert Morris hacks the Internet
As a graduate student at Cornell University in 1988, Robert Morris created what would come to be known as the first worm on the Internet. Morris has said he created the worm not for damage, but to give him an idea of the size of the web. In order to hide the worms origins at Cornell, Morris released it from MIT, unleashing it to exploit vulnerabilities in Unix sendmail, finger, and rsh/rexec. However, a design flaw caused the worm to replicate itself at higher levels than Morris has intended, overloading systems and causing damage significant damage.
After he was identified as the source of the worm, Robert Morris became the first person convicted under the Computer Fraud and Abuse Act in 1990. Morris was sentenced to three years of probation, 400 hours of community service, a fine of $10,050, and the costs of his supervision.
Vladimir Levin hacks Citibank
In what is seen by many as one of the first high-profile instances of financially-motivated hacking, Russian crime ring leader Vladimir Levin managed to gain access to accounts located in the Citibank network and stole millions of dollars in 1995.
Working as part of a larger crime group and using a computer based in London, Levin was able to get a list of customer codes and passwords that allowed him to log in many times over a several-week period and transfer money into accounts controlled by the crime organization. Officials said Levin managed to transfer $3.7 million illegally.
The FBI eventually caught up with Levin at a London airport and he was tried and convicted in the U.S. and sentenced to three years in jail in 1998. He was also ordered to pay Citibank $240,015 in restitution.
Jonathon James hacks NASA
Known by the hacker name c0mrade, Jonathon James was 16 when, in 1999, he hacked into the Marshall Space Flight Center in Huntsville, Alabama, and downloaded proprietary software for the International Space Station. The software supported the International Space Station's physical environment and was responsible for critical control of humidity and temperature for living in space.
NASA officials valued the documents stolen by James at around $1.7 million. The incident forced NASA to shut down its computer systems for three weeks and cost them about $41,000 to fix.