My wife is our county Treasurer. Her office recently purchased an outdoor drop box for property tax payments. County highway department employees installed the box. The pedestal for the drop box has a flange at the bottom. The flange is mounted to the sidewalk with 4 - 1/2" stainless steel wedge anchors with nuts & washers.
After I saw how the box was attached to the sidewalk, I told my wife that it would only take a couple of minutes for someone to unbolt the box & carry it away.
Other than welding the nuts to the anchors, are there any other options for making the box more theft proof?