(CNN) -- If you think there's a group of nerdish hackers somewhere hunched over their computers launching cyberattacks 24-7 on companies that have refused service to WikiLeaks, you're wrong.

Helping the hacking forum known as "Anonymous" and "Operation Payback" can be as simple as sending an e-mail to one of the many websites it uses -- and letting the hackers take control of your computer.

Anonymous claimed responsibility for disabling or disrupting the sites of MasterCard, Visa and PayPal this week. The attacks came on the heels of WikiLeaks leader Julian Assange's arrest.

"You don't have to be at your computer. All you've got to do is send Anonymous an e-mail that says, 'I consent to you using my computer, do whatever you like,' " and the people with Anonymous link to your computer, connect it with others who've consented, and use the collective force (among the machines) to launch these attacks," Gregg Housh, a 34-year-old internet activist based in Boston told CNN.

The Anonymous crew existed long before the WikiLeaks saga. In the past, they've launched attacks on websites of the Church of Scientology, the Motion Picture Association of America and the Recording Industry Association of America. But by comparison, those were relatively anonymous, as it were.

Now, thanks to worldwide media coverage of its name, the WikiLeaks story and some minor improvement to its attack tool, Anonymous has made a name for itself.

Housh responded to an e-mail sent by CNN to an Anonymous website asking for an interview. Housh, speaking by telephone, said he's only monitoring Anonymous' activity and has not participated in the WikiLeaks-related attacks.

Anonymous has no command structure and no spokesperson, said Housh. But it does have some collective discipline.

"Anonymous is nonexistent. We don't have members," he said. "If you want to go on [in a portal] and say, 'Let's attack this group and the majority of the people who are in that portal at that time agree, then that group will be targeted. If the majority of people present in the portal decide -- at that time -- that your suggested target is a dumb idea, nobody acts."

Network researcher Dr. Jose Nazario confirmed Housh's account of how the site works and how many people and computers are involved in the attacks.

Nazario is a researcher with Arbor Networks, a Chelmsford, Massachusetts, firm that tracks malicious activity on computer networks. Arbor Networks works for private sector clients with ISPs large enough to be the victims of attacks such as the ones MasterCard and Visa experienced. The firm also works with law enforcement.

Nazario has been monitoring Anonymous for a corporate client but would not say which one. He said about 1,500 people with computers based in the United States have been consistently chatting on the Anonymous site this week.

Many of those people have downloaded a tool that Anonymous created so that their computers can be linked, Nazario said. The tool is designed to repeatedly request data from servers, in turn overwhelming the servers and temporarily disabling sites.

So how many computers does it take to bring down a major corporation's Web site?

No more than 120, according to an analysis of Anonymous that Nazario performed this week. "It doesn't take a massive number of machines at all," he said.

"What's unusual about this is that people are volunteering their PCs," Nazario said. "You just don't see that often."

In addition to Housh, CNN talked online with several people who identified themselves as Anonymous volunteers. They would not give their names, but this is part of the conversation:

CNN: Who is Anonymous, Operation Payback? How do you work?

Anon: Anonymous is everyone, and everyone can be Anonymous. We are from different parts of the world with different professions working towards a common goal, following a common idea. We mainly operate via our IRC [Internet Relay Chat] rooms and social networking sites.

CNN: So, how did you come together over WikiLeaks? Was this spontaneous? Tell me how it started.

Anon: Operation Payback started as a demonstration against all things people were unable to change using legal means. Our primary goal is freedom of information. Any and all information. At first we were focused on issues concerning piracy (and we still are), but once the WikiLeaks fiasco occurred it was obvious we had to help. Our initial goal specifics were different, but we all share the common idea of free information.

Anon (continued) At the moment, we took a side track to support Julian Assange and WikiLeaks. While their methods may be controversial, they do demand transparency, which is something we definitely support. When we think we made our point (e.g. WikiLeaks accepted as whistleblower, without fear that they will be prosecuted), we will return to fighting copywrong.

While we can't say for certain what our ultimate goal is, the most important ones are - justice (not by current law, but by moral) - unlimited freedom of expression - taboo of censorship: nobody should silence somebody else.

CNN asked Housh if, as rumored, Twitter and Facebook would be Anonymous' next targets. Would customers of MasterCard, Visa or Amazon be hurt?

"They aren't here to hurt free speech. They aren't going to attack you," he answered. "You don't want to go after people, you want to go after the corporation. The people are not your enemy."

But the others who claim they are involved with Anonymous say it's not so clear-cut.

Here are more excerpts from CNN's online conversation with members who claimed to be part of Anonymous.

CNN: Do you see this expanding to disrupting the payment system at MasterCard?

Anon: Anything is possible ... Depends on who decides to join the cause. You never know ;) We can not say anything about our tactics at this time.

The ultimate goal for Operation Payback is just as fuzzy.

CNN: What's the end goal for you? What do you want to see happen as a result of Operation Payback?

Anon: Personally? An (sic) utopian society. This is just a new way to fight ... We will fight until this primary goal has been achieved ... We started this operatiion (sic) to save and protect the freedom to share information freely without any censorship. We will fight until this primary goal has been achieved.