A big difference is that when you protest in the streets, you take up one person's worth of space. So you need a lot of people to make an effective street prote

A big difference is that when you protest in the streets, you take up one person's worth of space. So you need a lot of people to make an effective street protest. But when you have your computer support a DDoS, it's generating, say, a thousand times more traffic than you would if you were normally visiting that site. And you don't even have to do anything once you start it. I would argue that if you organized 10 million people to repeatedly refresh their page on a site, that would be ok. They're doing the same thing that people who genuinely want to visit the site do (opening the site in a browser). It would take a ton of people to be effective, and it requires recurring effort. But when you use the leverage that computers give to make it take orders of magnitude fewer people and no recurring work, it's too easy for a small group to be disruptive. If a few thousand KKK members used Anonymous's technology to DDoS the NAACP website, would you be ok with that?