Final answer:
The statement is true; regularly reviewing and disabling old or unused accounts is a vital cybersecurity practice to reduce potential vulnerabilities within a system.
Step-by-step explanation:
Regularly reviewing user accounts on a system and disabling old or unused accounts is indeed a good step to take in hardening a system. This practice is true because it helps in reducing the attack surface that malicious actors can exploit. Unused accounts can become a security liability if they are compromised, as they may provide attackers with access to a system's network or sensitive data. Maintaining good account hygiene is a crucial part of cybersecurity practices.