Red Post - damaged

You may have noticed that two of the direction pointers on the Red Post outside the United Church are missing.

It appears that someone swung on them, presumably late at night having had a few pints too many, and the rivets broke. The two arms were found nearby and are now safely in the hands of the Dulwich Society, who as you will remember organised the Red Post installation on 2 October last year.

It appears that it will be a fairly simple matter to put them back. But how can it be prevented from happening again?