Note that removing or disabling "Private Browsing" will not make it impossible to delete private data like visited websites (history) or cache. There are a lot of ways to clear such data, either via [[Clear Recent History]] or directly by deleting the History in the Library or sidebar. Private Browsing makes it easier because all data is kept in memory and nothing is saved to disk, so nothing needs to be removed. If you want to see which sites have been visited then you should look at others means outside Firefox like a router or firewall with a password protected logging feature that can't be bypassed or a program like [http://www.wireshark.org/download.html Wireshark]. See also http://kb.mozillazine.org/Parental_controls