Educational institutions should keep student data private. Why? One reason is regulation, like FERPA in the US. Another reason is that it's simply the right thing to do.

Skilling extends Drupal's permissions system, adding restrictions based on course enrollment data.

Skilling enforces privacy at the field level, as well as at the entity level.

Skilling tightly controls data exports, to maintain privacy.

The privacy code is easy to audit.

Automated tests check that the privacy code works.