title: How to block Youtube by iptables
body: <p>I am trying to block Youtube connection with this command but it return an error msg: <code>getsockopt failed strangely: Operation not permitted</code>.</p>
  
  <p><code>iptables -I OUTPUT -m string --string "youtube.com" --algo bm --to 65535 -j DROP</code></p>
  
  <p>Any wrong with the command?</p>