Because computers and their media are sensitive to a variety of disruptions, a vandal can destroy hardware, software, and data. Human attackers may be disgruntled employees, bored operators, saboteurs, people seeking excitement, or unwitting bumblers. If physical access is easy to obtain, crude attacks using axes or bricks can be very effective. One man recently shot a computer that he claimed had been in the shop for repairs many times without success.
Physical attacks by unskilled vandals are often easy to prevent; a guard can stop someone approaching a computer installation with a threatening or dangerous object. When physical access is difficult, more subtle attacks can be tried, resulting in quite serious damage. People with modest technical knowledge of a system can short-circuit a computer with a car key or disable a disk drive with a paper clip. These items are not likely to attract attention until the attack is completed.