It looks like email addresses are visible when not logged in (obfuscated to protect the innocent):
Note that the email addresses are visible but the "Email" field is listed as "Private"
Looking through the privacy settings, I see that my username is my email address, and it is set to visible to Everyone and can't be changed. I think some users would not want this information to be public.
Can we have alternate (non-email) usernames? It would be nice to be able to login with either my registered email or username.