Ever since CD burners became inexpensive enough to be an attractive upgrade for most PC owners, CD production companies have been concerned with piracy. Because of this, CDs manufactures frequently alter the way they produce CDs so that copying them is more challenging. CDs come packaged with many different types of copying protection.
Since 2002, millions of copy-protected CDs have been released; not all of these CDs will work on all types of hardware. Some work only on CD players and not on CD-ROM players, DVD players, game consoles or car stereos. Consumers aren't able to back up their music from these CDs or even convert them to the poplar MP3 format.
One common method that has been used in the USA to protect CDs from being copied includes adding data to the CD copy that makes it unreadable to copiers; a second method includes altering the way the files are listed in the table of contents so that the CD can't be read by a CD-ROM.
No matter how frequently the video or music industries attempt to build the ultimate CD copy blocking system, enterprising people will find ways around them. For example, a student at Princeton University discovered a method to disable new copy protection that the CD manufacturer BMC is developing. This student found if you hold down the shift key while the CD begins to load onto your machine the Microsoft Windows AutoRun feature prevents the anti-piracy software from loading. This doesn't delete the program but bypasses the copy protection installation, making the music available for copying. Once such a discovery is made public on the Internet, the rest is history.