Until Anonymous came along, botnets were generally assembled by bad guys, organizations like the Russian mafia, Chinese hackers. They build botnets on the sly, installing malware on computers that turns them into zombies without their owners' knowledge. Each zombie can fire thousands of requests per second at a target website. So while you're working on that cover sheet for your TPS report, your computer is part of a joint effort to overwhelm a company's server and crash its website. That effort to crash a site is called a Distributed Denial of Service attack, or DDoS. The bad guys use DDoS attacks to extort money, but they can also use their botnets to send spam and steal people's identities. In 2009, the antivirus software firm Symantec said it had detected nearly 7 million botnets on the internet [sic].
Anonymous was the first group to build an operationalvoluntary botnet. By running the LOIC on your computer, you are, essentially, declaring your allegiance to Anonymous. You donate part of your computer's processing power to the cause. That causeor, if you prefer, the targetis determined by rough consensus among Anons.

Ten years ago it would have been infeasible for tens of thousands of individuals with no physical connection or central leadership to conceive, announce, and implement a massive act of civil disobedience against a significant Western power, crippling a portion of its online infrastructure in the process and to do all of this in a matter of days, and without anyone involved having to contend with the tear-gas-and-horseback response with which states have traditionally been in the habit of contending with mass action. But such a thing as this is happening today, and having been done once will almost certainly be done again repeatedly, increasingly, and with potentially significant consequences for the nation-state and implications regarding that which will perhaps someday come to replace it.
Anonymous' current campaign is the second of its kind; the first, in 2008, targeted the Church of Scientology with DDOS attacks, a series of in-the-flesh protests outside Scientology centers worldwide, the theft and dissemination of sensitive documents, and a variety of other steps all coordinated, or not, in a decentralized fashion that provides for no names, ranks, or central direction.