Here is a great article by Nicholas Pell from Mademan that give you a quick easy overview of the organisation known as Anonymous.

Anyone who hadn’t heard of Anonymous last year sure knows their, um, name now. Late last month, in the largest coordinated distributed denial of service (DDoS) attack ever, Anonymous took down the websites of the MPAA, RIAA, Universal Music Group, BMI, U.S. Copyright Office, Department of Justice, Belgian Anti-Piracy Federation, Warner Music Group, The White House, former Senator Christopher Dodd and the FBI. And new techno-assaults are going down every day. Clearly, these super computer geeks are on fire, so here’s all you need to know to sound smart at cocktail parties.

First off, where did “Anonymous” come from?

As with many aspects of this group, the facts are hazy. The term “Anonymous” is used on image boards (known as “chans”) by people who prefer to remain, well, anonymous. This then became an in-joke about an actual person named “Anonymous.” It wasn’t until around 2008 that the term began to refer to something more specific: A nebulous and leaderless hacktivist collective.

So who are they?

Hackers on steroids. An Internet hate machine.

No, really.

Anonymous is a loose and diffuse hacktivist group, consisting of three basic layers: First, the hard core of Anonymous (about 100 in number), the guys planning attacks and teaching at hacking schools. Second, the supporters of Anonymous (about 1,000). These cats hang out in the Internet relay chat (IRC) room and use a program called the Low Orbit Ion Cannon (LOIC) to carry out DDoS attacks and other assorted mayhem. The third layer consists of fellow travelers and supporters, who number in the hundreds of thousands.

Wait, what’s “hacktivism”?

A portmanteau of “hacking” and “activism,” hacktivism means using hacking techniques to make a political point. “Hacktivist” doesn’t always squarely apply to Anonymous. Sometimes they just pull pranks. Other times, such as with a DDoS attack, they aren’t really hacking. A DDoS raid is basically virtual loitering—overloading a site with requests until it crashes. It’s not too different from the Occupy Wall Street folks doing a flash mob outside of a bank.

And why are these guys so popular?

Anonymous have been pretty smart about picking targets. They lingered under the radar for years, first coming to national attention duringProject Chanology, a series of computer attacks and protests targeting The Church of Scientology, beginning in January 2008. However, Anonymous really gained traction when they did a solid for the Arab Spring. The group was involved in several attacks on key government websites of Arab dictatorships while the Arab streets were on fire last year, including releasing the names and private emails of government officials in Egypt, Bahrain, Jordan and Morocco. Anonymous might just be the most respected organization for under-30s in Arab countries.

Totally not scarier than Scientologists or anything…

What’s the deal with the masks?

The Guy Fawkes mask was popularized by the film V For Vendetta. The idea in the movie is that a leaderless resistance to tyranny arises around a symbol—the mask. Anonymous clearly find resonance with the idea of leaderless resistance and the power of symbols, but another explanation probably has some truth as well. As an ancient Anon proverb goes, it’s probably also “for the lulz.”

What else has Anonymous been involved in?

A lot of prankster stuff, particularly in the early days. But lately they seem to be hackers with hearts of gold. Other raids include racking up thousands of dollars in bandwidth costs for noted white supremacist Hal Turner and the Oregon Tea Party. Anon quickly came to the defense ofWikileaks, taking down the websites of PayPal, Mastercard, Visa and Amazon in retaliation for their anti-Wikileaks stance. They have continued to attack dictatorial and authoritarian governments such as Zimbabwe, Malaysia and Syria. They have also supported Occupy Wall Street and released sensitive information from governments and corporations alike as part of Operation AntiSec, short for “anti-security.” Whew.

So what kind of people do this stuff, exactly?

That’s the thing, no one really knows. “They hacked the CIA’s website, for crying out loud, and haven’t gone to jail for it,” says Josh Shaul, Chief Technology Officer of Application Security. “That takes skill. I’d be shocked to find that there aren’t people who are in charge of security for major banks or head programmers at major technology firms.” In practice, stunts get pulled, and Anonymous takes credit. There’s a general idea of what Anonymous is about, but everyone is free to act independently. You could go around calling yourself Anonymous right now if you wanted.

Really?

We wouldn’t recommend it. Anons don’t take kindly to poseurs. As their slogan goes: “We are Legion. We do not forgive. We do not forget. Expect us.”

How do I protect myself?

Basically by not being an Arab dictator, pro-SOPA member of Congress or random moron who decides he’s going to talk a bunch of smack. There are basically no examples of Anon going after someone who didn’t do something to deserve it.

What if I actually am an Arab dictator or something?

Sorry, dude. Even your copy of Norton Anti-Virus can’t save you now.