Anonymous had a busy year in 2011 pushing its hacker-activist agenda on companies around the Web, to the point where just the sound of the hacker group's name can send shivers down the spine of many a CIO.

Anonymous in 2011 took on everything from HB Gary to a Mexican cartel, from oil companies to banks, from NBC to a transportation site. The group has positioned itself as a kind of Internet-based Robin Hood; when it hacked banks, the group claimed it was helping "the 99%" by giving money from the banks back to the people who rightfully deserved it.

What have companies learned from this year of terror? The most that can be said is that corporate security needs to be shored up. At a conference panel in August it was evident that instead of battening down the security hatches, some companies were looking to just lessen the economic impact of a hack on their site.

Network World has assembled some of the key stories surrounding Anonymous, the reactions from enterprise IT and their advice for surviving an attack, in a special PDF report that is free with Insider registration. So take a peek and then register to receive this package of stories about hackers' doings last year and what can be done next.

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