What does a pen register do?

The pen register is a device that is specifically designed to capture outgoing call numbers from a telephone line. It functions by recording the phone numbers that a user dials, without intercepting the content of the calls themselves. This technology is often employed in law enforcement and investigative scenarios to monitor communication patterns and verify connections between individuals.

Understanding its purpose highlights the significance of privacy considerations, as the use of pen registers can lead to discussions about the balance between surveillance and personal rights. The other choices provided—recording video footage, tracking social media trends, and managing account information—do not relate to the specific functionality of a pen register, which is strictly focused on tracking outgoing telephone numbers. This clarity helps delineate technologies based on their applications and ethical implications within the context of surveillance and data privacy.