Under the Australian Privacy Principles or similar laws, there may be a requirement to protect personal information and not store data collected on the Joomla website.
In the component options is a setting "Do not store results", which if set to yes will delete the data collected once the notification email has been sent immediately after the form has been submitted. Obviously you'll need to include the fields in the email template so that you can obtain the information completed in the form.
Additionaly there is a "Encrypt form" setting, which will force the form submission to use SSL.
If you use the "Do not store results feature", you will not be able to use the results, reporting or stats areas of this component as there will be no data to display.