Okay, on a mass delete the message you will get before proceeding is:
IMPORTANT! Are you sure you want to delete the selected members? If you click 'Ok' the specified members will be deleted with no way to recover them. Any posts that they have made will remain intact, but will be set to owned by Anonymous.
So on a mass delete topics will all have the poster name of Anonymous. just fyi that is member 1.
One at a time will keep the posters name if you elect that option.
