some people have a curiosity, others do not have.
The concern is that you are living in an open world where every thing is accessable and when whyteknight said to put proxy ok, but what if he/she use internet out of your which does not have proxy.
If you have two childs one is curious and one is not, and you are having a medicine which is in reach, isn't it better to have this medicine in place where both children can not reach.