If for any reason there is a sudden rash of user accounts locking the following tools might be useful.
The AD console allows you to right click on a User and view the properties of the account. Under the ‘Account’ tab there is a checkbox that says “Account is locked.” If it is checked, the account is locked. Simply uncheck the box to unlock the account.
lockoutstatus.exe is a part of the Windows Resource Kit provided by Microsoft. It can provide you with detailed information about an account, why and when it locked out, and the ability to right-click and unlock the account within the tool (Instead of having to go through the AD).
unlock.exe is a freeware utility that easily monitors the AD for locked accounts. It can also unlock all accounts from the command line.
To view all locked accounts, run:
unlock . * -view
To specify which DC, run:
unlock AD-DC-P2.ad.domain.edu * -view
You can replace the asterisk with a particular user name or remove the -view flag to make it unlock the accounts. It can be integrated into scripts in case locking accounts happens to be a side-effect of what you’re trying to achieve.