If for some reason you do not want just anyone being able to open your form then you can hide your form by making it a private form. A private form can only be opened (and sent) while logged into a Formdesk account with any permission to the form or through a URL that directly enters a completed form, such as an edit URL or a workflow url.
Possible reasons to hide a form vary widely. Perhaps the form itself already contains sensitive information that may only be seen by certain people, perhaps because of the use of a lookup. Or maybe you invite a fixed panel of imported participants using the group email with an edit url and you do not want new submissions to be added. It may also be that you want to stop a form but that the outstanding workflows should still work.
To make your form private go to the ‘Settings’ tab, category ‘Security’.