How to query the locked/unlocked status of a bootloader using fastboot

fastboot oem device-info

On my ootb OnePlus One it says:
...
(bootloader)         Device tampered: true
(bootloader)         Device unlocked: false
(bootloader)         Charger screen enabled: false
OKAY [  0.005s]
finished. total time: 0.006s

The "Device tampered: true" seems to be a bit strange, since I did no tampering at all (unless booting into fastboot and/or recovery mode counts as "tampering"). Not yet anyway. Tongue I'm just about to root it.