What type of surveillance technology captures keystroke data?

Keyloggers are specialized software or hardware designed specifically to capture keystroke data as it is entered on a keyboard. This technology operates by recording every keystroke made by a user, which can then be reviewed later by an attacker to obtain sensitive information such as usernames, passwords, and other confidential data.

This capability makes keyloggers a particularly potent tool for cyber criminals, as they can operate covertly in the background without the user's knowledge. For instance, a keylogger can be installed on a system through a phishing attack or bundled with malicious software, allowing attackers to gather personal information exploited later for identity theft or unauthorized access to accounts.

In contrast, the other technologies mentioned serve different functions: web cameras are designed for capturing video images or streaming live video; network sniffers are used to analyze network traffic for monitoring and troubleshooting purposes; and firewalls are security devices designed to control the flow of incoming and outgoing network traffic based on predetermined security rules. None of these technologies are designed to specifically log keystroke data like keyloggers do.