DDOS is indeed normally conducted by botnets; however, Anonymous uses a tool called LOIC‡ to carry out DDOS attacks. Unlike a normal DDOS attack, people active

DDOS is indeed normally conducted by botnets; however, Anonymous uses a tool called LOIC‡ to carry out DDOS attacks. Unlike a normal DDOS attack, people actively coordinate the attack (ie: it's not automated), and apparently, do so from their own systems. I suspect a lot of the people who participate either aren't aware of the technical particulars, figure they'll be masked by large amounts of traffic, or just don't care. ‡ http://en.wikipedia.org/wiki/LOIC http://en.wikipedia.org/wiki/LOIC