This is where deleted posts go to await actual deletion.
Once a post or thread has been deleted, it will remain in the Lockbox for forty-five (45) days before it is deleted permanently. That way, if someone (accidentally or maliciously) deletes a post that should not have been deleted, there is a way to restore it.
Only forum moderators and administrators can view the Lockbox – other users will not even see it on the guild site. On a paid site, the administrators and moderators have the option of restoring posts that have been deleted and are currently sitting in the Lockbox.
There is no manual delete option for posts in the Lockbox for security reasons – that way, if a forum moderator wants to trash the forums on a guild site, the site owner or another moderator can fix the damage caused.