For security purposes, the classified ads function can be enabled if it is being used on your site or disabled if not in use.
If not in use, disabling the ads will reduce spam posts and will also make the area inaccessible if a user has a link to the page. If the page is disabled, the user going to the classified ads link will be redirected to the home page.
The Classified Ads can be managed under Master Settings Custom Settings
Under the 'Custom Settings' section, in the 'Enable Classifieds' field choose 'Yes' to enable or 'No' to disable