Weak security in payment industry opens door to credit card thefts. More than 70 retailers and payment processors have disclosed breaches since 2006, involving tens of millions of credit and debit card numbers, according to the Privacy Rights Clearinghouse. Meanwhile, many others likely have been breached and didn’t detect it. Even the companies that had the payment industry’s top rating for computer security, a seal of approval known as PCI compliance, have fallen victim to huge heists. Merchants that decide to hire an outside auditor to check for compliance with the PCI rules need not spend much. Though some firms generally charge about $60,000 and take months to complete their inspections, others are far cheaper and faster.