export AD passwords

I am looking for an easy way to export the username  and encrypted passwords from AD?
I have a network of over 3000 users I have inherited and apparently most of the users have never had to change there password before. I want to get a list of who is still using the "default" password so I can force them to change..
I know the passwords are encrypted in AD but I would assume if multiple users have the same password the encrypted password will be identical across all users.. If not then exporting the data will be of no value..