It's not a single person or two who had a password 12345, it's like a half of the office?!

Wow, when you count 123456 too, it is a big chunk of the office. Not to mention the others that had 12345 as part of their password.

I wonder if this is an IT policy gone bad. Perhaps the guy who set it up used 12345 as the default and, of course, nobody ever changed it.

I learned a long time ago to use a somewhat complex password when setting up new accounts, because otherwise 3 years later, they will be using the insecure temp password you gave them.

Or force them to change the password on first logon? And disallow weak passwords?