How did the Sony copy-protection software placed on CDs in 2005 create computer security concerns?

In 2005, Sony implemented a controversial form of digital rights management (DRM) by including hidden software on certain music CDs. When these discs were inserted into a computer, the software automatically installed a rootkit without the user's explicit knowledge or consent.1

This created significant computer security concerns for several reasons:

• Hidden Vulnerabilities: By operating as a rootkit, the software concealed its presence and activities from the user and the operating system, creating a security loophole that malicious actors could exploit to hide other malware or gain unauthorized access to the system.1
• Unauthorized Monitoring: The software was designed to track and report back to Sony regarding the listener's habits, which raised serious privacy concerns regarding the unauthorized collection of user data.1
• System Instability: Like other intrusive DRM measures, these hidden files could interfere with normal computer operations, potentially limiting software installations or causing conflicts with existing system files.1

Following widespread public outcry and legal action, Sony eventually recalled the affected CDs and discontinued the use of rootkits in its copy-protection measures.1