A federal judge has granted final approval, to a settlement by Sony BMG Music Entertainment of several class-action lawsuits filed against it over the use of copy-protection software on its CDs.

The settlement, which received preliminary approval in January this year, covers consumers who purchased CDs with XCP or MediaMax copy-protection software that left their computers vulnerable to hackers, as also allowed the company to track their listening habits.

Earlier, Sony was sued in three separate class-action lawsuits, which were consolidated into this settlement. The suits were launched in November 2005, soon after computer science researchers disclosed that Sony's XCP software used dangerous "rootkit" techniques to cloak itself after installation.

Rootkit software is normally used by hackers to hide their malware from system tools and antivirus products, and Sony was widely criticized for using this potentially dangerous software.

However, anyone who purchased, received, or used CDs containing the digital-rights management (DRM) software after August 1, 2003, is covered under the agreement. The settlement allows consumers to exchange old CDs for new ones without the copy protection technology, and requires Sony BMG to provide consumers with a patch to remove the software from their computers.

Moreover, people who bought the affected CDs are also entitled to a cash payment of $7.50, and one album download from a selection of 200 titles. And customers who bought a CD containing the MediaMax software are entitled to free album downloads.

In a statement, Cindy Cohn, legal director, the Electronic Frontier Foundation, said that this settlement gets music fans what they thought they were buying in the first place, music that will play on all their electronic devices without installing tricky software.

Meanwhile, Sony BMG has said it is pleased with the court's verdict.