Report for Cookied v Non Cookied users

Run a Smart List for leads that have an Original Referrer value. Or for leads that have at least one Visited Web Page activity.

Note these are the people with at least one associated cookie. That's a subset of the total cookies that have been set in leads' browser(s). You won't know if Person A (who is in your database) has a cookie until that cookie becomes associated with their lead.