The user can only hide/show indicator by editing the dconf file which is not very "elementary" UI.
It is not immediately obvious how to re-show the widget through the UI once hidden without adding new code to system components however.
If this is for privacy purposes then maybe rendering the indicator inactive may be a better option and set insensitive and change the icon to be be crossed out (like muted sound indicator). It may then be toggled on-off with a middle-click and a tooltip used for discoverability like other indicators.