deleting guess permission

[zabbix]

hi all, I wanna give no permission to anybody who access my php frontend.
I have no permission for guess user and in this way guess :
-cannot access configuration
-cannot access Monitoring and Inventory
-BUT STILL ACCESS TO REPORTS

How can I avoid this feature?
(I want guess user can do and see nothing)

Thanks all

[swaterhouse]

not sure how to do this. My guess is its not easy since a feature listed in 1.5.2beta for inclusion in 1.6 is: "User 'guest' can be disabled"