When USB memory sticks first appeared on the market, a lot of security folks went mad. After all, they are just perfect for spreading viruses around, not to mention stealing data.

Figures from the Information Security Breaches Survey reveal that smart phones, iPods and USB memory sticks pose a significant problem for the security of businesses. For example, around a third of businesses tell their employees not to use these kinds of devices, but then do nothing to lock down PCs so that using them is not possible. Only 10% of those companies interviewed for the survey encrypt the confidential data stored on these devices, meaning that if they contain company data and are lost, their ability to compromise company security is great.

Dennis Szerszen, spokesman for security software firm Secure Wave, said in some sense the risk portable storage systems pose has been around since the emergence of the floppy disk.

"But," he told the BBC News website, "that was just 360 kilobytes of risk not four gigabytes that can be transferred in five minutes."