Disable tty login on display/keybd


I have built an Ubuntu Core 16 image a while ago, but what I do need to disable the TTY login, after providing a USB key with the auto-import.assert file on it? I have disabled the first tty1 login, but what about the rest of the TTYs? I have tried disabling and masking it (getty@tty2, etc) to no avail. image