Enabling or disabling login

You can activate or deactivate a user's ability to log in using the admin portal. Use the Edit link to the right of Sign-in status to accomplish this task. There's also a bulk option to enable and disable user login. Look for Edit sign-in status in the bulk user menu.

To disable a user sign-in with PowerShell, use the following:

Get-MsolUser -UserPrincipalName jdeer@liquidhgdev.onmicrosoft.com | Set-MsolUser -BlockCredential $true