How do I reset all user passwords to 123 with drush or SQL?
Yes, you can do this using Drush, with following steps (e.g.):

1.Generate a password hash using following command:

$ cd [/var/www/html/drupal7]
$ php scripts/password-hash.sh '123'


2.Now run following drush command:

$ drush sql-cli
mysql &gt; UPDATE users SET `pass` = 'pasted_big_hash_from_above' WHERE uid &gt; 1;


Update pasted_big_hash_from_above with password hash generated using php command in step #1.