Blocking extremists will make anti-terrorism surveillance more difficult as the organizations go underground  A major risk with any extremist organization is that its members, when put under significant legal pressure, will go underground, or find other means of communicating, or use any ISPs that not blocking extremist content. The power of ISPs, or the state for that matter, to actually stop the development of extremist networks is limited, as they will be able still to organize in secret, or even semi-publicly, via social networks and hidden websites that evade detection by the censors. As Mark Burgess, director of the World Security Institute warns ““too much focus on closing down websites could also be counter-productive, since it likely forces terrorist websites to go underground to the so-called ‘deep’ or hidden web.” [1]  Terrorist groups visible profile would be blunted, but it would not guarantee any positive gains in terms of stamping down on the number of extremists. Indeed, when extremists are driven from public channels it will be ever harder for the government to keep track of their doings and of their leaders. The result of this censorship is a more careful organization that now has a sense of victimhood against the society that censors it, which it can use to encourage even more extreme acts from its members and can spin to its advantage during recruitment efforts. By leaving them in the open extremists feel more comfortable acting within the confines of the law and are thus less dangerous, even if they are more visible.  [1] Andrews, S., “The dark side of the web”, PC Pro, 9 March 2010,