And there is help from across the Atlantic in the form of Paul McCartney, who is holding a concert in October to benefit post-attack relief efforts.

CNN: Celebrities pitch in to help

Before Saturday's incident, the U.S. had announced plans to leave the post that came under attack.

CNN: 8 U.S. troops killed in battle with militants in Afghanistan

Members of the collective would often post a short Twitter message after a successful hack attack, providing a link to a Pastebin post which in turn contained details of the data they had copied from the target's computer servers.

BBC: Pastebin puts Anonymous spat behind it