Devices marked "ICE" which can hold a significant amount of data and are readable by a computer are sold, typically USB flash drives with password-protected data entry providing read-only access to emergency medical data. However, it has been pointed out by a staff nurse with experience in trauma and critical care that such devices are worse than useless, at least in most situations in the UK, as medical computer systems are designed not to accept USB storage devices due to the risk of computer viruses. Additionally, there is no guarantee that ICE information even pertains to an unconscious person carrying it; using incorrect information can lead to patient harm and legal liability.