The result of these DDoS attacks is that a website overloads with information and shuts down. This, in turn, is intended to force the owner of the website to comply with whatever Anonymous has demanded.
Before we go any further, let's listen to Anonymous explain their perception of this illegal activity. Keep in mind that the interview embedded here was done through Russia Today--commonly known as RT--a news station funded by the Russian Government, with an extreme bias in favor of the illegal antics Anonymous uses to frustrate the United States Government. You can read more about that here.
To save yourself time, here's a few notes: at the timeline of 1:30, the Anonymous speaker begins to explain that DDoS attacks are "not malicious" and are like "cyber sit-ins". At 4:55, the Anon claims to be baffled by the ten year maximum sentence for conducting a DDoS attack. If you're wondering what actually happens when an Anon gets caught and sentenced, you can read about the sentencing of an Anon involved with the attacks against Scientology websites here.
So, is a DDoS attack really just a "cyber sit-in"? Well, let's compare DDoS and an actual sit-in. When a group of people gather in front of a store to protest, would you consider that an attack? It doesn't seem to remotely qualify as one; people standing with signs is hardly a threat to anyone's well-being. So why is it that a DDoS attack is referred to by everyone--including Anonymous--as an attack? It seems that Anonymous has betrayed their own argument by the mere usage of that terminology.
They use the term "DDoS attack" precisely because it is intended to have the effect of an attack. An actual store-front protest can't prevent customers from entering the store, nor the store from conducting business; a DDoS attack disables the store/website entirely. The Anon in the video says that, "...we're not breaking windows of buildings; we're not destroying parts of websites." This is akin to saying, "I didn't get any scratches on your car when I stole it. I just took it for a ride."
Furthermore, consider that at a real store-front protest, you can see the protesters. You can respond to them. And when you take away that aspect of being able to visually grasp the situation and confront your opponents, you start delving into the realm of terrorism. This is one of the core differences between an actual protest and a DDoS attack. The DDoS attack is meant to induce terror; "You can't see us, you can't find us, and you can't stop us from abusing you. Now give us what we want."
Anonymous clearly is a cyber-terrorist organization--a criminal organization fueled by criminal minds. Fortunately, their delusional nature will ultimately be their undoing, much like the capture of Hannibal Lecter by Will Graham:
Will Graham: "I know that I'm not smarter than you."
Hannibal Lecter: "Then how did you catch me?"
Will Graham: "You had disadvantages."
Hannibal Lecter: "What disadvantages?"
Will Graham: "You're insane."
