As a Marketo Admin, you can mark a specific field as “sensitive” so its values never get pre-filled in forms, thereby protecting users’ sensitive data.
This feature will be enabled for all Marketo instances on the evening of Tuesday, May 11.
Click Field Management.
Find and select your desired field.
Select the Mark Field as Sensitive checkbox.
And that’s it! Going forward, any Marketo forms enabled with pre-fill will not display data for the selected field.