Commercial corporations, foreign intelligence agencies, and even teenage crackers may capitalize on these electronic emanations. The government has taken action to prevent criminals from receiving these emanations by requiring that all governmental computers that are used to store and process classified information be equipped with special physical shielding. There have also been instances where criminals have recorded the noise from a key-and-ribbon computer printer and then play the recording to decode the keys. However, this problem has recently declined because of the use of laser printers that cannot be decoded (). .
The last form of physical computer crime is known as degradation of service. In a criminal sense, degradation of service is defined as the deliberate attack on a system with the intent to slow down or shut down service. There are two types of attacks that fall under this category. The first deals with a form of electronic sabotage that involves the actual destruction or impairing of data or equipment. "Turning off power or sending messages to system software telling it to stop processing are examples of the first type of attack - a classic denial of service"(). The other type of attack is called flooding, or sometimes spamming or wedging. During this type of attack, the intruder puts high levels of pressure on the systems" ability to service requests and eventually the system completely quits functioning. An example of flooding is the Internet worm. As the worm expanded across networks and systems, it created new processes that congested the systems and caused other programs to shut down ().
Personnel Crimes.
The second major category associated with computer crime deals with breaches of .
personnel security. Personnel crimes deal with intruders either pretending to be someone that they are not or by committing a crime against another person via computer. One of the most common types of personnel crimes is called masquerading.