Hello World

# pw lock username
# pw unlock username

USER LOCKING
     The pw utility supports a simple password locking mechanism for users; it
     works by prepending the string `*LOCKED*' to the beginning of the pass-
     word field in master.passwd to prevent successful authentication.

     The lock and unlock commands take a user name or uid of the account to
     lock or unlock, respectively.  The -V, -C, and -q options as described
     above are accepted by these commands.