SAN FRANCISCO -- Hoping to crack down on music piracy, five major record labels have quietly begun selling CDs containing technology that foils attempts by customers to copy the songs onto blank discs ...

For the last several months, consumers in ordinary record stores around the world have unwittingly been buying CDs that include technology designed to discourage them from making copies on their PCs.

Perhaps in an effort to try to calm down people who have been unable to listen copy-protected CDs on their PCs, Sony's Label Gate CDs will allow customers to decode music from the CD onto their PC.

Two leading copy-protection technology companies announced Tuesday that they are merging, in a deal that could help speed the move of controversial copy-proof music CDs to market. Macrovision, a Santa ...