Content filtering on Firefox for Android can be site specific, add on specfic etc. If it is the addon please manage your add ons from the Settings menu. If it is for a specific site or on the phone check out [http://www.ekoob.com/android-parental-control-web-filter-block-websites-11546/] This is a nice add on as well for content filtering on Firefox for Android [https://addons.mozilla.org/en-US/firefox/addon/procon-latte/ Procon Latte] If you have any other questions, please post back.