PCI DSS standard has taken a beating from critics, security experts and CSOs virtually since the day it appeared in its earliest form in 2004. The standard is designed to keep payment card data secure by restricting access to the data and keeping it segmented from other information. The major credit card companies, including Visa, MasterCard and American Express, require that organizations that handle payment card. The same tactics and techniques that enable attackers to compromise a normal network, intercept traffic and get to the valuable data can be used to exploit PCI-compliant networks.
Source: https://threatpost.com/pci-compliance-no-real-obstacle-compromises-030112/76276/