AP
The AP did an article on anonymous file-sharing and quoted me:
"I'm not aware of independent testing or review to verify the claims that people are making," he said.
The article as a whole seems to suggest that anonymous file-sharing may be impossible. But I think it's perfectly possible: I would just be worried about trusting your privacy to Brand X File-Sharing Software without having a clear idea of how it tries to protect your identity and whether that method is secure against attacks you're concerned about.
One important lesson of security and privacy is that things marked "Secure" or "Private" need not be.