Fraud by Input Manipulation
Fraud by input manipulation occurs where false or misleading data are input into a computer to achieve a specific criminal purpose: for example, decreasing the amounts entered into a store inventory database to hide the theft of a product.
Fraud by Output Manipulation
Fraud by output manipulation occurs where data or software is input into a computer in order to affect what the computer outputs: for example, using a stolen bank account number to make unauthorized withdrawals from an ATM.
Computer forgery occurs whenever a computer is used to create a fraudulent document or illegally alter an otherwise legal document: for example, using a computer to create a fake identification badge.
Fraud by Program Manipulation
Program manipulation occurs when data or software in a program is altered to commit or facilitate a crime. For example, software code known as "packet sniffers" can be added to a program to record valuable information passing across a network such as credit card access numbers.
On December 29, 2009, Albert Gonzalez pleaded guilty to perpetrating one of the largest computer fraud cases in history. Over a four-year period, Gonzalez and his accomplices, using program and output manipulation schemes, were able to steal more than 150 million credit card and ATM debit card numbers.
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