revoke — revoke a
    character device
The revoke program revokes the character
    devices using
    revoke(2).
    When used on a TTY, calls like
    read(2),
    write(2)
    and
    ioctl(2),
    will be aborted immediately, effectively causing login sessions to be
    terminated.
The revoke program first appeared in
    FreeBSD 8.0.