Shortly after the announcement and launch of the Moto E, Motorola has added the device to its Bootloader Unlock service meant for Android enthusiasts and developers. The addition qualifies the versions of the device as sold in North America, South America and Europe with access to the tools necessary to unlock the bootloader on the device if so desired to ease testing and development of alternative Android builds, such as CyanogenMod and other variants.
As is typical of such unlocking, the service does void the manufacturer warranty and leaves device issues directly in the hands of the user, so anyone wanting to dip their toes into Android ROMs and development with the Moto E would be best served buying the device as a secondary device for such purposes rather than buying it solely as a primary phone, since such development is liable to render devices inoperable without some experience in switching ROMs.