David, I think that Sebastian Greger (and perhaps some of the GDPR) is really concerned about anonymity; not privacy. But I think you have responded reasonably. I don’t think one can expect privacy when acting publicly. Imagine if newspapers had to get permission to quote something I said publicly (especially something controversial)? Or a radio or television news cast couldn’t use footage of my public acts because of “privacy”? I don’t see any level or ethical basis (USA law) for Sebastian‘s position. I expect as the GDPR is implemented we’ll see some challenging consequences of the rules.