Anytime sensitive information is collected by our forms we recommend users to enable SSL .
To ensure that the sensitive content is not transmitted via email, we also suggest enabling the 'Mask Email' option. Masking a field output will obfuscate the field data and replace the contents with asterisks (*) in your notification emails.
As a final measure Pro and higher plans have the ability to encrypt specific field data so that the only way to view this data is by logging into your account and view via the Data Manager. (Please See How to activate Field Encryption)