Extended Copy Protection
Extended Copy Protection (XCP) is a copy protection scheme for compact discs developed by the British company First 4 Internet, which, as of 2005, is used on some CDs distributed by Sony. It has come under much criticism for installing software that alters the functionality of the Microsoft Windows operating system, and hides itself so that it is difficult to find or remove; this software has been termed a root kit by technical experts, and some consider it to be similar to trojan horses or other malware. There are also concerns that its cloaking technique could be used by other malware "piggybacking" on it to ensure that it, too, is hidden from the user's view.
Since it is specific to Windows, XCP has no effect at all on other operating systems such as Linux or MacOS, meaning that users of those systems not only do not suffer the potential harm of the root kit, but they also are not impeded in any way from "ripping" the normal music tracks on the CD, thus defeating the purpose of having copy protection in the first place.
There is much speculation about whether the actions taken by this software under the Windows OS are a violation of various laws against unauthorized tampering with computers, and can subject Sony and First 4 Internet to legal liability. However, the mere act of attempting to view or remove this software in order to determine or prevent its alteration of Windows may itself be a civil or criminal offense under anti-circumvention legislation such as the USA's Digital Millennium Copyright Act.
A patch to remove the cloaking of the software has already been released, and First 4 Internet reports that upcoming versions of XCP will not use the same techniques.