In recent years, Online Social Networks (OSNs) are one of the most popular interactive medium to communicate, share and distribute a considerable amount of human life information. The best entertainment for the people is given in the form of Social Networking sites. But the fundamental issues in OSNs are to give the users the ability to control the information posted on their private walls and to validate the data inputted by the users. The aim of the present work is therefore to propose and experimentally examining an automated system, called Filtered Wall (FW) able to filter undesired information from OSN user wall and to check whether the data inputted by the user is valid or not. The system use a Machine Learning (ML) based text classifier to enforce customizable Content-based Filtering and it give users the ability to control the information posted on their own private space to avoid that undesired information to be displayed in online social networking environment and to validate the data inputted by the user.