"This policy brief is divided into four parts. First, we provide basic definitions and terminology concerning blocking/filtering. This is followed by an outline of relevant international standards on freedom of expression. We then address the fundamental issues underlying the use of filters and blocking measures. Finally, we provide comprehensive recommendations for legislators, policy and decisions makers in this area. Summary of recommendations: 1. Blanket filtering must be prohibited by law; 2. Filtering should be user-controlled and transparent; 3. Any requirement to block content must be provided by law; 4. Blocking should only be ordered by an independent and impartial court or adjudicatory body; 5. Blocking orders must be strictly proportionate to the aim pursued." (Executive summary)