What version are you running?
1.7.5
What's the URL of the page this enhancement relates to, if any?
http://demo.reviewboard.org/
Describe the enhancement and the motivation for it.
demo.reviewboard.org and reviews.reviewboard.org are public reviewboard servers that publish users' email addresses by default. I think that the default should be changed. At least they seem to require that someone be logged in before showing email addresses, but anybody can create an account, and AFAIK there's no separate confirmation step that discourages fake accounts from being created (and maybe that deserves its own enhancement request).
I don't know if this is something that admins can configure. If it isn't, maybe it should be; I think it makes sense to publish addresses by default for a private server.
What operating system are you using? What browser?
Windows 7 x64 with Firefox 19.0.2