The usb port blocker allows you to deny access to any usb socket this is useful to stop flash drives and external hard drives being connected to a computer or server to copy sensitive data stop the delivery of viruses keyloggers and other malicious programs it will also stop people connecting and charging mobile devices insert lock into a usb port with the key squeeze the side buttons and pull out to remove the lock insert the key into the usb lock and pull out without squeezing t