 whatever happens to the worshippers during their prayers or outside of their prayers is the responsibility of the one who built the mosque as it is not permissible to decorate the mosque in any way.
وكلما طرأ على المصلين فى صلاتهم وفى غير صلاتهم فهو فى رقبة البانى للمسجد.. إذ لا يحل تزيين المسجد بوجه..