How to make personal data fields non editable
That survey uses a Webform-civicrm form. The 'existing contact' field has had 'Field Locking' applied to the Name and Email fields (first time i saw this feature - nice addition!).

if you want to achieve the same directly in civicrm profile when you add a field to the profile you have the option to set it to read-only.

ADDENDUM: Nathan below comments that "I believe this is available in Webform CiviCRM 7.x-4.15 based on the notes and code in the change comparison listed here: github.com/colemanw/webform_civicrm/compare/7.x-4.14...7.x-4.15"