Missing Web Page Activity - Cookies blocked?

We have some leads filling out forms (embedded on the website) that are not showing any web page activity in the Lead Activity. My immediate thought was the leads have not allowed cookie tracking so this is expected Marketo behavior. But when I looked at the Original Referrer field to test that theory, I'm seeing data. The data values are primarily the landing page that the form is embedded on. Q: Is it possible to have Original Referrer data, on a new lead that has declined cookie tracking or blocked cookie tracking at the browser level?