A random survey of more than 100 businesses by Ground Labs, a software company, found that every one of them had credit card details unwittingly stored on its computers.One company that was adamant it had no credit card details on record was found to have more than 20 million card numbers on computers throughout its network, Ground Labs said.The finding supports fears that many businesses take inadequate steps to safeguard customers' credit card details."Holding credit card details in this way is a breach of Payment Card Industry Data Security Standards compliance obligations and can attract up to a £500,000 fine by the Information Commissioner's Office in a case of a data breach," Ground Labs said.Even businesses that claimed to be compliant with agreed global standards for credit card data security held rogue details, the survey found. "There are various possible reasons for this, all linked to standard computer processes such as browser 'caches' or email duplications," the company said.Mohamed Zouine of Ground Labs added: "We have more than 1,000 businesses across the UK and Europe that have used our software and every single business found erroneous card records in its IT systems."We found that even those businesses that believe that their systems are clean are carrying records that could be easily acquired by hackers."A similar routine test of 50 consumers' personal computers found that all but one of them held credit card details without the owner's knowledge.