I create a new site collection called site1 through user1 who is also farm admin.
When I search something in site1, it brings all results i.e. not only from this site but other site collections also (because I am using custom search scope "All Sites")
I created another AD user called user2
I gave READ permissions to user2 in site1 by adding it into VISITORS group.
Then I logged into site1 as user2 and searched something but it is only showing results from other site collections and not this current site1.
I then added user2 in site1 SITE OWNER group but still same problem. It is not showing results from current site collection.
Why is that? That user2 is the owner of site1 but still no results!? While in case of user1 it works who is also farm admin.