The Chrome OS team is experimenting with a new USB Safeguard feature that will stop new USB devices from running on the lock screen. Existing devices will continue running.
This is applicable only to new USB devices that you connect while the screen is locked. You will need to unlock Chrome OS for these new devices to start working.
This is to protect the Chromebook from running malicious code through USB devices. Imaging yourself using a Chromebook in a coffee shop and someone being able to connect a USB device and do something tricky on your device.
This flag is currently available in the Chrome OS Canary Channel.
Name: Block new USB devices at the lock screen.
Description: Prevents newly connected USB devices from operating at the lock screen until Chrome OS is unlocked to protect against malicious USB devices. Already connected USB devices will continue to function. – Chrome OS
I am hoping that this feature will be enabled by default when ready. I would prefer that way, with switch to toggle this off from the Settings app in case I have other requirements.
What do you think? Is this a useful feature? Let me know in comments!