Which of the following is a privacy concern in information systems?

Unauthorized data collection is a significant privacy concern in information systems because it involves the gathering of personal or sensitive information without the consent of the individuals involved. This concern is particularly pertinent in an era where organizations have access to vast amounts of data, and often, this data can be collected seamlessly through various digital interactions, whether online purchases, social media usage, or mobile app interactions.

When data is collected without permission, it raises ethical questions about user privacy and can lead to potential misuse of information, such as identity theft, discrimination, or surveillance. For individuals, unauthorized data collection can erode trust in institutions and lead to a feeling of being constantly monitored or exploited. This is why regulations such as GDPR in Europe and various privacy laws around the world focus on consent and transparency in data collection practices.

In contrast, while data encryption, cloud storage security, and data redundancy all relate to the handling and protection of data, they do not specifically address the core issue of whether data is collected without user consent. Therefore, unauthorized data collection is the most pressing privacy concern among the options given.