Data diddling refers to the act of altering or manipulating data before, during, or after it is entered into a system. This can be done by unauthorized individuals with malicious intent in order to deceive or defraud the system or its users. Data leakage refers to the unauthorized release or disclosure of sensitive data, hacking refers to unauthorized access or intrusion into a computer system, and hijacking refers to the unauthorized takeover or control of a system or network. Therefore, data diddling is the most appropriate term to describe the act of changing data before, during, or after it is entered into the system.