Richard Stallman
Stallman, in typical outspoken fashion, rails against cloud computing in a recent Guardian interview:

"It's stupidity. It's worse than stupidity: it's a marketing hype campaign."

Interesting. Well, no one ever said the Stallman wasn't single-minded. His priorities are built so that the privacy concerns are the only thing that matters, so that giving control of your data to the cloud is the dumbest thing you can do. Well, it's an awfully myopic perspective. But maybe the world needs extremists like Stallman, especially because we all know to take him with a giant grain of salt by now. Still, I don't live in the world he lives in.