Final answer:
A hacker is someone who maliciously invades computer systems to steal or destroy information, which can be for various malicious purposes including identity theft and espionage. These cyber intrusions can cause significant disruptions and financial harm. Governments and militant groups may also engage in hacking for strategic purposes.
Step-by-step explanation:
Someone who maliciously invades a computer system to steal or destroy information is known as a hacker. Hackers have a range of techniques to infiltrate computer systems, such as breaking into websites, engineering ways for individuals to click on malicious links, and deceiving people into divulging sensitive information. The intention behind such actions can vary from benign curiosity to malicious goals like identity theft, espionage, disruption of services, or the spread of disinformation.
Governments and militant groups have also been known to weaponize cyberspace, utilizing hacking to acquire secret intelligence, interfere with satellite communications, cripple networks, and disrupt internet services. Offensive cyber operations can serve as a form of modern warfare, contributing to geopolitical instability and conflict.
When it comes to identity theft, also known as "True-name Fraud," this occurs when a hacker wrongfully obtains and uses a person's personal identification, credit, or account information without permission. The stolen identity can then be exploited to deplete savings accounts or incur substantial debts, leading to severe financial and personal implications for the victim.