I think it’s necessary to forbid using mobile phone in some cases. For example in classes or meetings, the ringing is very disturbing. Although you may turn your mobile phone into the mute mode, it will distract you from classes thus reduce your study efficiency. And sometimes it’s impolite to use a mobile phone in some public occasion such as important conferences. Furthermore, the microwave radiation of a mobile phone will disturb the normal operating of special machines in some places such as hospital and laboratory. So forbidding using a mobile phone in some cases is good for you as well as the people surrounding you.