Facebook: Does it need to address the opt-in, opt-out issue?

Facebook CEO Mark Zuckerberg's performance at D8 showed the company sweats the privacy issue---literally---but the open question is whether the company needs to address the opt-in issue.

As we all know, Facebook's privacy settings need users to opt-out. Zuckerberg talked about friction and sharing, but largely dodged Walt Mossberg's questions about whether users should just have the option to opt-in.

Here's the video and all the coverage of Zuckerberg's D8 talk. Should everything be opt-in?

And regarding the sweating privacy issue: